WorldWideScience

Sample records for selective return migration

  1. Income, self-selection, and return and onward interprovincial migration in Canada.

    Science.gov (United States)

    Newbold, K B

    1996-06-01

    "Estimated returns to migration based on comparison of individual migrants may be biased owing to self-selection in the migration process. Using data derived from the 1986 Canadian census, I will study the effects of expected wage differentials in determining the return or onward migration decision of nonnative adults aged 20 to 64 years. Evidence was found that return migrations were in the 'right' direction, as they are observed to respond to provincial economic variables (that is, average employment growth and income levels) in a rational manner. After accounting for self-selectivity, I found that...return migrants...are negatively selected, and experience lower income levels, following the return migration, than onward migrants would have, had they chosen the return migration option. This drop in expected wages decreases the propensity associated with making a return migration. Despite this drop in income, the large proportion selecting the return migration option suggests the importance of the province of birth in the mental map of nonnative migrants." excerpt

  2. Return Migration and Working Choices

    OpenAIRE

    TANI, Massimiliano; MAHUTEAU, Stéphane

    2008-01-01

    Collective Action to Support the Reintegration of Return Migrants in their Country of Origin (MIREM) This paper uses the recent survey carried out in the framework of the MIREM project on returnees to Algeria, Morocco and Tunisia and studies the duration of emigration and the labour force status upon returning. The results suggest that age and the year of emigration play a central role in the migration decision, but they do not support the hypothesis that the duration of migration is deter...

  3. Return Migration to Mexico: Does Health Matter?

    Science.gov (United States)

    Arenas, Erika; Goldman, Noreen; Pebley, Anne R; Teruel, Graciela

    2015-12-01

    We use data from three rounds of the Mexican Family Life Survey to examine whether migrants in the United States returning to Mexico in the period 2005-2012 have worse health than those remaining in the United States. Despite extensive interest by demographers in health-related selection, this has been a neglected area of study in the literature on U.S.-Mexico migration, and the few results to date have been contradictory and inconclusive. Using five self-reported health variables collected while migrants resided in the United States and subsequent migration history, we find direct evidence of higher probabilities of return migration for Mexican migrants in poor health as well as lower probabilities of return for migrants with improving health. These findings are robust to the inclusion of potential confounders reflecting the migrants' demographic characteristics, economic situation, family ties, and origin and destination characteristics. We anticipate that in the coming decade, health may become an even more salient issue in migrants' decisions about returning to Mexico, given the recent expansion in access to health insurance in Mexico.

  4. Husbands' return migration and wives' occupational choices

    NARCIS (Netherlands)

    Mahe, Clotilde

    2017-01-01

    Exploiting the documented effect of migration on occupational choice upon return to their origin country with data from Egypt, we establish a link between return migration of men and their wives' time use through within-couple occupational interdependence. Seemingly Unrelated Regression model

  5. DESIGNING THE RETURN MIGRATION OF ROMANIAN STUDENTS

    Directory of Open Access Journals (Sweden)

    Magdalena VELCIU

    2017-05-01

    Full Text Available Romanian youth migration is an increasing phenomenon, due to subjective and objective factors as economical reasons, professional carrer and increasingly more international competition for talent. In these circumstances, the present article aims to evaluate determinant factors that contribute to the decision of Romanian graduates to return national labour market. We sustain that young Romanians consider carefully and hardly decide their professional future. A particular attention is given to their personal reasons and motivations as well as family and friends network. For designing returning factors we present the results of a questionnaire survey, asking young pupils and students about their future educational way and personal reasons underlying the decision to study in a foreign country and taking into consideration the returning decision. As far international student migration is seen as a first step to migration for work, our work desires to fight for returning home of Romanian well-educated graduates.

  6. Return migration as failure or success? : The determinants of return migration intentions among Moroccan migrants in Europe

    NARCIS (Netherlands)

    de Haas, H.; Fokkema, T.; Fihri, M.F.

    2015-01-01

    Different migration theories generate competing hypotheses with regard to determinants of return migration. While neoclassical migration theory associates migration to the failure to integrate at the destination, the new economics of labour migration sees return migration as the logical stage after

  7. Return Migration among Elderly, Chronically Ill Bosnian Refugees

    DEFF Research Database (Denmark)

    Handlos, Line Neerup; Olwig, Karen Fog; Bygbjerg, Ib Christian

    2015-01-01

    Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from...... Denmark and the role of health issues in their decision to return. It is based on semi-structured interviews with 33 elderly, chronically ill Bosnian refugees who have moved back to Bosnia and Herzegovina, and 10 elderly, chronically ill Bosnian refugees who have remained in Denmark. The interviews show...

  8. Return Migration as Failure or Success?: The Determinants of Return Migration Intentions Among Moroccan Migrants in Europe.

    Science.gov (United States)

    de Haas, Hein; Fokkema, Tineke; Fihri, Mohamed Fassi

    Different migration theories generate competing hypotheses with regard to determinants of return migration. While neoclassical migration theory associates migration to the failure to integrate at the destination, the new economics of labour migration sees return migration as the logical stage after migrants have earned sufficient assets and knowledge and to invest in their origin countries. The projected return is then likely to be postponed for sustained or indefinite periods if integration is unsuccessful. So, from an indication or result of integration failure return is rather seen as a measure of success. Drawing on recent survey data ( N  = 2,832), this article tests these hypotheses by examining the main determinants of return intention among Moroccan migrants across Europe. The results indicate that structural integration through labour market participation, education and the maintenance of economic and social ties with receiving countries do not significantly affect return intentions. At the same time, investments and social ties to Morocco are positively related, and socio-cultural integration in receiving countries is negatively related to return migration intentions. The mixed results corroborate the idea that there is no uniform process of (return) migration and that competing theories might therefore be partly complementary.

  9. Return Migration among Elderly, Chronically Ill Bosnian Refugees

    DEFF Research Database (Denmark)

    Handlos, Line Neerup; Olwig, Karen Fog; Bygbjerg, Ib Christian

    2015-01-01

    Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from D...... of illness, health did matter. Viewed as physical, social and mental well-being in line with WHO's definition of health, health was indeed one of the most important factors when the decision to return was made....... that physical health, in the sense of the absence of illness and easy access to necessary health-care services and medicines, was not highly prioritized when the decision was made whether or not to return. However, if health is regarded more broadly as involving more than mere physical health and the absence......Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from...

  10. The Determinants of Return Migration: Evidence for Kosovo

    Directory of Open Access Journals (Sweden)

    Ardiana Gashi

    2015-12-01

    Full Text Available Return migration represents a potentially important contributor to economic development for countries that are large exporters of labor. This paper provides an analysis of the determinants of return migration to Kosovo, a country with an especially high level of recent emigration. The findings of this investigation suggest that there is a non-linear relationship between the age of the migrant and their probability of returning. In addition, the more educated migrants and those that have acquired additional education whilst abroad are more likely to return, whereas recent migrants, those that possess permanent resident status and have their family abroad are less likely to return. As expected, the stronger the family ties of a migrant with their home country, the more likely they are to return. Finally, migrants that are expected to invest in businesses in Kosovo are more inclined to return. Together these findings suggest that return migration may be an important contributor to economic development in Kosovo and policies are outlined that could strengthen this contribution.

  11. The Effects of Return Migration on A Gozitan Village.

    Science.gov (United States)

    King, Russell; Strachan, Alan

    1980-01-01

    A lengthy two-cycle migration pattern is typical of young males on the Maltese island of Gozo. Their typical final return to and reintegration into the natal community impacts the local population, housing development, and the visual appearance of the area. These findings closely parallel prior research results. (SB)

  12. Return migration: changing roles of men and women.

    Science.gov (United States)

    Sakka, D; Dikaiou, M; Kiosseoglou, G

    1999-01-01

    This article addresses changes in gender roles among returning migrant families. It focuses on Greek returnees from the Federal Republic of Germany and explores changes in task sharing behavior and gender role attitudes resulting from changes in the sociocultural environments. A group of return migrants was compared with a group of non-migrants, both living in villages in the District of Drama, Greece. Groups were interviewed to investigate the extent to which each spouse shared house tasks, as well as their attitudes towards sharing and gender role in the family. The t-test for independent samples was used to determine mean differences between the two groups. In addition to demographic variables, those concerning the "time lived abroad" and the "number of years in Greece" after return were inserted into a series of regression analyses. Findings showed that migrants' task sharing and gender role attitudes were influenced differently by the migration-repatriation experience and subsequent cultural alternation. Results also suggest that migrant couples either take on new patterns of behavior or maintain traditional ones only when these were congruent with the financial aims of the family or can be integrated into living conditions in Greece upon return. Furthermore, migrants seem to adopt a more "traditional" attitude than non-migrants toward the participation of women in family decision making. From the study, it is suggested that gender role change is an on-going process influenced by the migration-repatriation experience, as well the factors, which accompany movement between the two countries.

  13. Forced migration and mental health: prolonged internal displacement, return migration and resilience.

    Science.gov (United States)

    Siriwardhana, Chesmal; Stewart, Robert

    2013-03-01

    Forced internal displacement has been rising steadily, mainly due to conflict. Many internally displaced people (IDP) experience prolonged displacement. Global research evidence suggests that many of these IDP are at high risk for developing mental disorders, adding weight to the global burden of disease. However, individual and community resilience may act as protective factors. Return migration may be an option for some IDP populations, especially when conflicts end, although return migration may itself be associated with worse mental health. Limited evidence is available on effects of resettlement or return migration following prolonged forced internal displacement on mental health. Also, the role of resilience factors remains to be clarified following situations of prolonged displacement. The public health impact of internal displacement is not clearly understood. Epidemiological and interventional research in IDP mental health needs to look beyond medicalised models and encompass broader social and cultural aspects. The resilience factor should be integrated and explored more in mental health research among IDP and a clearly focused multidisciplinary approach is advocated.

  14. Labour migration and rural development in Egypt. A study of return migration in six villages.

    Science.gov (United States)

    Reichert, C

    1993-01-01

    An analysis of the impact of labor migration on social change in 6 rural villages (Shanawan and Kafr Shanawan north of Cairo, Kafr Yusuf and Tambul el Kubra near Simbalaween, and Abu Girg and Bani Walims in Minya governate) in Egypt was conducted in 1987-88. Since the 1991 Gulf war, the political environment, the labor markets, and the structure of migration opportunities have changed. An estimated 5% of rural households might have been directly affected by migrants' departure from Kuwait and Iraq. Data collection involved a household census survey of 8620 households, of which 2483 were migrants, including 1765 return migrants. A sample of return migrant (639) was interviewed about their migration experiences. Participant observation was also conducted among migrants and nonmigrants, and case studies were developed. Villages were demographically and socioeconomically very different; migration ranged from 18.5-434.2%. Structural change was measured on a scale of 1 to 6 in terms of population size, literacy of household heads, share of agricultural occupations, share of new red brick houses, and availability of infrastructural or institutional facilities. The probability of having a household with a migrant member increased with the rural character of the village. Landholdings or other major household variables were unrelated to migration. Rural outmigration was almost exclusively male, the average age was 29.6 years, and the average stay was 2.6 years. Migration destination was specific to individuals but affected by occupation and family or village resources. Professionals were overrepresented in Saudi Arabia, and farm and unskilled laborers or the unemployed were overrepresented in Iraq. Remittances from international migration have contributed along with the economic reforms of Sadat to new, private initiatives from all strata in rural society. 74.3% of returnees stated that improvement in income and living standards was the motivation for migration; many motives

  15. The effects of integration and transnational ties on international return migration intentions

    Directory of Open Access Journals (Sweden)

    Hein de Haas

    2011-12-01

    Full Text Available While return migration is receiving increasing attention, there is still insufficient insight into the factors which determine migrants' intentions and decisions to return. It is often assumed that integration in receiving countries and the concomitant weakening of transnational ties decreases the likelihood of returning. However, according to alternative theoretical interpretations, return migration can also be the outflow of successful integration in receiving countries. Drawing on a data set of four African immigrant groups in Spain and Italy, this articlereviews these conflicting hypotheses by assessing the effects of integration and transnational ties on return migration intentions. The results of the analysis suggest that socio-cultural integration has a negative effect on return migration intentions, while economic integration and transnational ties have more ambiguous and sometimes positive effects. The results provide mixed support for the different hypotheses but question theoretical perspectives that unequivocally conceptualizereturn migration and transnationalism as causes and/or consequences of "integration failure".

  16. OECD migration, welfare and skill selectivity

    DEFF Research Database (Denmark)

    Pedersen, Peder; Pytlikova, Mariola; Smith, Nina

    into 27 OECD countries over the period of 12 years, 1989-2000. Using a fixed effects panel data model, we analyze the determinants of the migration flows during the latest decade. We study whether there are significant selectivity effects in international migration flows, i.e. whether the countries...

  17. The effects of integration and transnational ties on international return migration intentions

    NARCIS (Netherlands)

    de Haas, H.; Fokkema, C.M.

    2011-01-01

    While return migration is receiving increasing attention, there is still insufficient insight into the factors which determine migrants’ intentions and decisions to return. It is often assumed that integration in receiving countries and the concomitant weakening of transnational ties decreases the

  18. The probability of return conditional on migration duration: evidence from Kosovo

    Directory of Open Access Journals (Sweden)

    Kotorri Mrika

    2017-12-01

    Full Text Available The aim of this paper is to conceptualise the migration duration decision within the expected utility maximisation framework, and from that to derive and estimate an empirical proposition. For this purpose, the conceptual framework in Kotorri (2015 is extended where households decide to return to the home country conditional on their migration duration. In the empirical analysis, the Cox proportional hazards model is employed. This analysis is the first to investigate migration duration based on a random sample stemming from the Kosovo census of population conducted in 2011. The findings suggest rather mixed support for the household approach. The hazard to return decreases with income but not nonlinearly. The results indicate that household return migration behaviour is influenced by demographic characteristics, psychic income, and political factors.

  19. Internal migration and the health of the returned population: a nationally representative study of China.

    Science.gov (United States)

    Zhang, Luwen; Liu, Shuaishuai; Zhang, Guoying; Wu, Shaolong

    2015-07-28

    China had 236 million internal migrants in 2012 and the majority of them migrated from rural to urban areas. The research based on medical and epidemical records found that the migrants had worse health than the urban residents, but the household and working place investigations reported better health status. The sick or unhealthy migrants are likely to return to their hometowns, which in turn may cause a report bias or over-estimation of the health status of rural-to-urban migrants in China. This paper explores the association of migration status and the physical and psychological health of Chinese internal migrants. Nationally representative household survey data from the China Labor-force Dynamics Survey 2012 (CLDS) were used to analyze the association between the migration status and the health status of internal migrants in China. Migration status of the respondents was measured by hukou status and migration experience and all respondents were divided into four groups: returned population, migrant population, urban residents, and rural residents. Health status of respondents was measured by self-reported physical and psychological health. Migration experience was associated with the physical health of the returned population. The physical health of the returned population was worse than the migrant population and was distinguished by age and sex. The physical health status of migrant population was significantly better than rural residents, but not significantly better than urban residents. However, the association between migration status and psychological health was not statistically significant. Besides migration status, the socioeconomic status (SES) had a positive correlation with both physical and psychological health status, while occupational hazards exerted negative influence. The results indicate a tight association between migration experience and health status. The internal unhealthy migrants were more likely to return to their hometown and the

  20. Return Migration among Elderly, Chronically Ill Bosnian Refugees: Does Health Matter?

    Science.gov (United States)

    Handlos, Line Neerup; Olwig, Karen Fog; Bygbjerg, Ib Christian; Kristiansen, Maria; Norredam, Marie Louise

    2015-10-12

    Elderly migrants constitute a considerable share of global return migration; nevertheless, literature on the health aspects of the return migration among these migrants is still scarce. This study explores the significance of return migration among elderly, chronically ill Bosnian refugees from Denmark and the role of health issues in their decision to return. It is based on semi-structured interviews with 33 elderly, chronically ill Bosnian refugees who have moved back to Bosnia and Herzegovina, and 10 elderly, chronically ill Bosnian refugees who have remained in Denmark. The interviews show that physical health, in the sense of the absence of illness and easy access to necessary health-care services and medicines, was not highly prioritized when the decision was made whether or not to return. However, if health is regarded more broadly as involving more than mere physical health and the absence of illness, health did matter. Viewed as physical, social and mental well-being in line with WHO's definition of health, health was indeed one of the most important factors when the decision to return was made.

  1. Return migration of highly skilled scientists and engineers to Morocco : return or circulation ?

    OpenAIRE

    Gaillard, A.M.; Gaillard, Jacques

    2015-01-01

    The qualification level of the emigrating Moroccans rose steadily in the 1990s, and especially since the year 2000. At present, an estimated 20 per cent of the highly qualified Moroccans live abroad. Student migration, which accounts for a large part of this 20 per cent, is contributing substantially to keeping this level high. For the last 20 years Morocco has been testing actions to mobilise and reconnect its S&T diaspora. The related special programmes and institutions are discussed and an...

  2. Internal migration, earnings, and the importance of self-selection.

    Science.gov (United States)

    Ahmed, A M; Sirageldin, I

    1994-01-01

    This paper analyzes the impact of internal migration on earnings within the human capital model framework. Since migrants constitute a non-random sample of population, the endogenous nature of migration decision warrants necessary correction for the selectivity bias in their earnings function. The Mincer-type earnings model is thus augmented to determine the extent of this bias. Besides estimating the standard Mincerian earnings model, the paper also attempts to verify the learn-as-you-go proposition by introducing migration duration variables in the earnings model. Based on the household level Population, Labor Force, and Migration (1979-80) survey data, the analysis yields the following important conclusions: (i) the data allowed a meaningful estimation of Mincerian earnings function for migrants and non-migrants; (ii) the level of schooling was one of the important determinants of the distribution of income both for migrants and nonmigrants--the four categorical variables of education were in general statistically significant with expected signs, implying that the hypothesis of a positive relationship between income and education was accepted; (iii) the rates of return to education improved systematically with higher levels of education, thus confirming the notion that education serves as a signalling device; (iv) the age-income profile was almost linear for migrants but showed concavity for nonmigrants; (v) the presence of sample-selection was observed for migrants; and (vi) even after controlling for the influence of personal characteristics, i.e., education and experience, the long-standing migrants earned relatively more at the destination than the more recent migrants.

  3. New Skills, New Jobs: Return Migration, Skill Transfers, and Business Formation in Mexico.

    Science.gov (United States)

    Hagan, Jacqueline Maria; Wassink, Joshua

    2016-11-01

    Numerous studies have documented a high propensity for self-employment and business formation among return migrants relative to non-migrants. The literature points to the importance of remitted savings, migration duration, and number and types of jobs abroad for business formation upon return. Implicit in this scholarship is the assumption that migrants acquire not only financial capital, but also human capital, which expands their opportunities upon return. Empirical work has demonstrated how the transfer of formal human capital, such as language skills and professional credentials, influences the mobility pathways of professional return migrants. More recent research has also found that the transfer of informal human capital, such as social and technical skills learned on the job, shape the mobility pathways of return migrants with little schooling. Absent from this scholarship, however, are studies that directly test the relationship between the transfer of informal human capital and the odds of business formation among return migrants. In this paper, we address this gap. Using a multidimensional skills variable, which includes social, technical, and English language competences, we measure and test the relationship between skill acquisition and transfer and business formation among return migrants. Drawing on findings from a survey of 200 return migrants and 200 non-migrants in Mexico, we show that return migrants who successfully acquire and transfer new skills across the migratory circuit often leverage their new knowledge to launch businesses. Our findings have wide implications for how social scientists conceptualize and measure human capital formation across the migratory circuit.

  4. Uncertain programming models for portfolio selection with uncertain returns

    Science.gov (United States)

    Zhang, Bo; Peng, Jin; Li, Shengguo

    2015-10-01

    In an indeterminacy economic environment, experts' knowledge about the returns of securities consists of much uncertainty instead of randomness. This paper discusses portfolio selection problem in uncertain environment in which security returns cannot be well reflected by historical data, but can be evaluated by the experts. In the paper, returns of securities are assumed to be given by uncertain variables. According to various decision criteria, the portfolio selection problem in uncertain environment is formulated as expected-variance-chance model and chance-expected-variance model by using the uncertainty programming. Within the framework of uncertainty theory, for the convenience of solving the models, some crisp equivalents are discussed under different conditions. In addition, a hybrid intelligent algorithm is designed in the paper to provide a general method for solving the new models in general cases. At last, two numerical examples are provided to show the performance and applications of the models and algorithm.

  5. Self-selection and intermunicipal migration in Canada.

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    Islam, M N; Choudhury, S A

    1991-02-01

    "This paper investigates individual intermunicipal migration behaviour in Canada within the context of a human capital model that adjusts for the migrant's selectivity in computing expected income gains. In addition to the typical regional determinants of migration, housing and labour market characteristics are found to influence intermunicipal migration significantly, the effects differing with age. Structural coefficients remained more or less stable during the decade 1971-1981. It is shown that the failure to adjust income gains for selectivity bias results in an underestimation of the migration-impacts of income gains and municipal-specific factors." excerpt

  6. Health Selection, Migration, and HIV Infection in Malawi.

    Science.gov (United States)

    Anglewicz, Philip; VanLandingham, Mark; Manda-Taylor, Lucinda; Kohler, Hans-Peter

    2018-04-27

    Despite its importance in studies of migrant health, selectivity of migrants-also known as migration health selection-has seldom been examined in sub-Saharan Africa (SSA). This neglect is problematic because several features of the context in which migration occurs in SSA-very high levels of HIV, in particular-differ from contextual features in regions that have been studied more thoroughly. To address this important gap, we use longitudinal panel data from Malawi to examine whether migrants differ from nonmigrants in pre-migration health, assessed via SF-12 measures of mental and physical health. In addition to overall health selection, we focus on three more-specific factors that may affect the relationship between migration and health: (1) whether migration health selection differs by destination (rural-rural, rural-town, and rural-urban), (2) whether HIV infection moderates the relationship between migration and health, and (3) whether circular migrants differ in pre-migration health status. We find evidence of the healthy migrant phenomenon in Malawi, where physically healthier individuals are more likely to move. This relationship varies by migration destination, with healthier rural migrants moving to urban and other rural areas. We also find interactions between HIV-infected status and health: HIV-infected women moving to cities are physically healthier than their nonmigrant counterparts.

  7. The Demographic Crisis and Global Migration - Selected Issues

    Science.gov (United States)

    Frątczak, Ewa Zofia

    2016-01-01

    Currently the world is undergoing a serious demographic shift, characterised by slowing population growth in developed countries. However, the population in certain less-developed regions of the world is still increasing. According to UN data, as of 2015, (World...2015), 244 million people (or 3.3% of the global population) lived outside their country of birth. While most of these migrants travel abroad looking for better economic and social conditions, there are also those forced to move by political crises, revolutions and war. Such migration is being experienced currently in Europe, a continent which is thus going through both a demographic crisis related to the low fertility rate and population ageing, and a migration crisis. Global migrations link up inseparably with demographic transformation processes taking place globally and resulting in the changing tempo of population growth. Attracting and discouraging migration factors are changing at the same time, as is the scale and range of global migration, and with these also the global consequences. The focus of work addressed in this paper is on global population, the demographic transformation and the role of global migrations, as well as the range and scale of international migration, and selected aspects of global migrations including participation in the global labour market, the scale of monetary transfers (remittances) and the place of global migration in the UN 2030 Agenda for Sustainable Development (Transforming...2015) and the Europe of two crises (Domeny 2016).

  8. Kinetic evolutionary behavior of catalysis-select migration

    International Nuclear Information System (INIS)

    Wu Yuan-Gang; Lin Zhen-Quan; Ke Jian-Hong

    2012-01-01

    We propose a catalysis-select migration driven evolution model of two-species (A- and B-species) aggregates, where one unit of species A migrates to species B under the catalysts of species C, while under the catalysts of species D the reaction will become one unit of species B migrating to species A. Meanwhile the catalyst aggregates of species C perform self-coagulation, as do the species D aggregates. We study this catalysis-select migration driven kinetic aggregation phenomena using the generalized Smoluchowski rate equation approach with C species catalysis-select migration rate kernel K(k;i,j) = Kkij and D species catalysis-select migration rate kernel J(k;i,j)= Jkij. The kinetic evolution behaviour is found to be dominated by the competition between the catalysis-select immigration and emigration, in which the competition is between JD 0 and KC 0 (D 0 and C 0 are the initial numbers of the monomers of species D and C, respectively). When JD 0 −KC 0 > 0, the aggregate size distribution of species A satisfies the conventional scaling form and that of species B satisfies a modified scaling form. And in the case of JD 0 −KC 0 0 −KC 0 > 0 case. (interdisciplinary physics and related areas of science and technology)

  9. Social Security Contributions and Return Migration Among Older Male Mexican Immigrants.

    Science.gov (United States)

    Aguila, Emma; Vega, Alma

    2017-06-01

    For decades, scholars have studied the effects of immigration on the U.S. social security system. To date, this research has been primarily limited to migrants within the United States and does not consider those who return to their countries of origin. We estimate the proportion of male Mexican return migrants who contributed to the U.S. social security system and analyze their socioeconomic characteristics and migration histories. We also estimate the proportion that receive or expect to receive U.S. social security benefits. Using probit regression on the 2012 Mexican Health and Aging Study (MHAS), we describe the predictors of having contributed to the U.S. social security system among Mexican males in Mexico aged 50 years and older who at some point lived in the United States. We find that 32% of male return migrants reported having contributed to the U.S. social security system, but only 5% of those who contributed, received or expected to receive benefits. Those who reported having contributed spent more years in the United States and were more likely to be U.S. citizens or legal permanent residents than those who did not contribute. Immigrants often pay Old-Age, Survivors, and Disability Insurance taxes using legitimate or illegitimate social security numbers and return to their home countries without collecting U.S. social security benefits. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Metropolitan migration and population growth in selected developing countries.

    Science.gov (United States)

    1983-01-01

    The purpose of this article is to estimate the components of metropolitan population growth in selected developing countries during 1960-1970 period. The study examines population growth in 26 cities: 5 are in Africa, 8 in Asia, and 13 in Latin America, using data from national census publications. These cities in general are the political capitals of their countries, but some additional large cities were selected in Brazil, Mexico, and South Africa. All cities, at the beginning of the 1960-1970 decade had over 500,000 population; Accra, the only exception, reached this population level during the 1960s. Some cities had over 4 million residents in 1970. Net migration contributed about 37% to total metropolitan population growth; the remainder of the growth is attributable to natural increase. Migration has a much stronger impact on metropolitan growth than suggested by the above figure: 1) Several metropolitan areas, for various reasons, are unlikely to receive many migrants; without those cities, the share of metropolitan growth from net migration is 44%. 2) Estimates of the natural increase of migrants after their arrival in the metropolitan areas, when added to migration itself, changes the total contribution of migration to 49% in some metropolitan areas. 3) Even where net migration contributes a smaller proportion to metropolitan growth than natural increase, the rates of net migration are generally high and should be viewed in the context of rapid metropolitan population growth from natural increase alone. Finally, the paper also compares the components of metropolitan growth with the components of growth in the remaining urban areas. The results show that the metropolitan areas, in general, grow faster than the remaining urban areas, and that this more rapid growth is mostly due to a higher rate of net migration. Given the significance of migration for metropolitan growth, further investigations of the effects of these migration streams, particularly with

  11. Different forms, reasons and motivations for return migration of persons who voluntarily decide to return to their countries of origin.

    Science.gov (United States)

    Callea, S

    1986-03-01

    Although the 1973 oil crisis did not have the drastic effects on immigration which were originally feared, it did end a period of quasi-liberal immigration policy, establish intense and effective international cooperation on immigration, and arouse great interest in immigration studies and research. This paper analyzes the situations arising as a result of the petroleum shortage and focuses on the conditions relating to the return of emigrants to Southern European countries. This new research draws attention to the following fundamental aspects of the immigration problem: 1) the emigrant's return to his homeland cannot be considered a factor in development; it is a positive element in development only if the right socioeconomic conditions exist in the country of origin. 2) Concern for children's education is one of the most common reasons for return. 3) A large percentage of emigrants are satisfied with their work abroad. 4) An emigrant's return potential is wasted due to the slight use that is made of the resources he offers. 5) Returning workers most often want to set up an independent enterprise. 6) Savings are generally used to buy a house or farm. 7) Vocational level does not increase significantly between emigration and returning, though this increase becomes greater the longer the emigrant stays abroad. 8) The number of returning emigrants is too slight to bring about any change in the country of origin. 9) Incentives and subsidies to encourage return have not had a considerable impact on the decision to return. Callea recommends that officials of the country of origin posted abroad be assigned to counsel returning emigrants on finding employment, attending vocational development courses, obtaining housing, accruing interests and savings, and on the problems and perspectives of sociocultural reintegration.

  12. The views of migrant health workers living in Austria and Belgium on return migration to sub-Saharan Africa.

    Science.gov (United States)

    Poppe, Annelien; Wojczewski, Silvia; Taylor, Katherine; Kutalek, Ruth; Peersman, Wim

    2016-06-30

    The negative consequences of the brain drain of sub-Saharan African health workers for source countries are well documented and include understaffed facilities, decreased standards of care and higher workloads. However, studies suggest that, if migrated health workers eventually return to their home countries, this may lead to beneficial effects following the transfer of their acquired skills and knowledge (brain gain). The present study aims to explore the factors influencing the intentions for return migration of sub-Saharan African health workers who emigrated to Austria and Belgium, and gain further insight into the potential of circular migration. Semi-structured interviews with 27 sub-Saharan African health workers in Belgium and Austria were conducted. As mentioned by the respondents, the main barriers for returning were family, structural crises in the source country, and insecurity. These barriers overrule the perceived drivers, which were nearly all pull factors and emotion driven. Despite the fact that only a minority plans to return permanently, many wish to return regularly to work in the healthcare sector or to contribute to the development of their source country. As long as safety and structural stability cannot be guaranteed in source countries, the number of return migrants is likely to remain low. National governments and regional organizations could play a role in facilitating the engagement of migrant health workers in the development of the healthcare system in source countries.

  13. Selective Migration among Southern Blacks: A Reinterpretation of Lee (1951).

    Science.gov (United States)

    Wolff, JosePh L.

    1979-01-01

    Explanations of differences in IQs of Northern and Southern Blacks focus on selective migration (hereditarians) or environmental causes such as education, discrimination and cultural deprivation. In this paper the environmentalist position is questioned and certain neglected features of Lee's data are construed as providing strong evidence for…

  14. Passing through - reasons why migrant doctors in Ireland plan to stay, return home or migrate onwards to new destination countries.

    Science.gov (United States)

    Brugha, Ruairí; McAleese, Sara; Dicker, Pat; Tyrrell, Ella; Thomas, Steve; Normand, Charles; Humphries, Niamh

    2016-06-30

    International recruitment is a common strategy used by high-income countries to meet their medical workforce needs. Ireland, despite training sufficient doctors to meet its internal demand, continues to be heavily dependent on foreign-trained doctors, many of whom may migrate onwards to new destination countries. A cross-sectional study was conducted to measure and analyse the factors associated with the migratory intentions of foreign doctors in Ireland. A total of 366 non-European nationals registered as medical doctors in Ireland completed an online survey assessing their reasons for migrating to Ireland, their experiences whilst working and living in Ireland, and their future plans. Factors associated with future plans - whether to remain in Ireland, return home or migrate to a new destination country - were tested by bivariate and multivariate analyses, including discriminant analysis. Of the 345 foreign doctors who responded to the question regarding their future plans, 16 % of whom were Irish-trained, 30 % planned to remain in Ireland, 23 % planned to return home and 47 % to migrate onwards. Country of origin, personal and professional reasons for migrating, experiences of training and supervision, opportunities for career progression, type of employment contract, citizenship status, and satisfaction with life in Ireland were all factors statistically significantly associated with the three migratory outcomes. Reported plans may not result in enacted emigration. However, the findings support a growing body of evidence highlighting dissatisfaction with current career opportunities, contributing to the emigration of Irish doctors and onward migration of foreign doctors. Implementation of the WHO Global Code, which requires member states to train and retain their own health workforce, could also help reduce onward migration of foreign doctors to new destination countries. Ireland has initiated the provision of tailored postgraduate training to doctors from

  15. The Effect of Exit Strategy on Optimal Portfolio Selection with Birandom Returns

    OpenAIRE

    Cao, Guohua; Shan, Dan

    2013-01-01

    The aims of this paper are to use a birandom variable to denote the stock return selected by some recurring technical patterns and to study the effect of exit strategy on optimal portfolio selection with birandom returns. Firstly, we propose a new method to estimate the stock return and use birandom distribution to denote the final stock return which can reflect the features of technical patterns and investors' heterogeneity simultaneously; secondly, we build a birandom safety-first model and...

  16. Identifying the Return on Investment for Army Migration to a Modular Open Systems Approach for Future and Legacy Systems

    Science.gov (United States)

    2017-04-05

    Identifying the Return on Investment for Army Migration to a Modular Open Systems Approach for Future and Legacy Systems Phillip Minor...Authorization Act (NDAA) of 2015, cites the modular open systems approach (MOSA) as both a business and technical strategy to reduce the cost of system ...access the service over the network. Combine the advances cited above with the emergence of systems developed using the modular open systems approach

  17. Does International Migration Pay Off? The Labor Market Situation of Finnish Return Migrants Based on Longitudinal Register Data

    Directory of Open Access Journals (Sweden)

    Saara Koikkalainen

    2016-12-01

    Full Text Available International mobility is a form of flexible labor market adaptation available for young Nordic nationals who have the privilege of relatively easy return if life abroad does not work out. The article considers mobility as a labor market transition and examines the pre- and post-migration situation of two Finnish return migrant groups—those who lived abroad in 1999 and in 2004—based on longitudinal register data. It considers the consequences of return for an individual migrant: is it a form of failure in labor market integration in the country of destination or rather a sign of success whereby the skills, resources, and experiences gained abroad are brought back to the country of origin. Migrants who leave Finland nowadays often opt to move to other Nordic countries and are younger, more educated, and have a better socio-economic status than previous migrant generations. The article demonstrates that international migration does not deteriorate the returnees’ labor market status. While re-entry into the Finnish labor market may take some time and flexibility, mobility seems to pay off and have beneficial consequences: return migrants earn higher taxable incomes and have lower unemployment rates than their peers who only stayed in the national labor markets..

  18. Selection or network effects? Migration flows into 27 OECD countries, 1990-2000

    DEFF Research Database (Denmark)

    Pedersen, Peder J.; Pytlikova, Mariola; Smith, Nina

    Recent migration patterns show growing migration pressure and changing composition of immigrants in many Western countries. During the latest decade, an increasing proportion of the OECD immigrants have been from poor countries, where the educational level of the population is low. The migration ...... evidence that selection effects have had a major influence on the observed migration patterns until now. This may partly be explained by restrictive migration policies in many OECD countries which may have dampened the potential selection effects....

  19. Selection or Network Effects? Migration Flows into 27 OECD Countries, 1990-2000

    DEFF Research Database (Denmark)

    Pedersen, P.J.; Pytlikova, Mariola; Smith, Nina

    Recent migration patterns show growing migration pressure and changing composition of immigrants in many Western countries. During the latest decade, an increasing proportion of the OECD immigrants have been from poor countries, where the educational level of the population is low. The migration ...... evidence that selection effects have had a major influence on the observed migration patterns until now. This may partly be explained by restrictive migration policies in many OECD countries which may have dampened the potential selection effects....

  20. Heterogeneous returns to U.S. college selectivity and the value of graduate degree attainment

    OpenAIRE

    Seki, Mai

    2013-01-01

    Existing studies on the returns to college selectivity have mixed results, mainly due to the difficulty of controlling for selection into more-selective colleges based on unobserved ability. Moreover, researchers have not considered graduate degree attainment in the analysis of labour market returns to college selectivity. In this paper, I estimate the effect of a U.S. four-year undergraduate program’s selectivity on wages, including graduate degree attainment. I control for both observed a...

  1. 77 FR 37078 - Product Change-Parcel Select and Parcel Return Service Negotiated Service Agreement

    Science.gov (United States)

    2012-06-20

    ... POSTAL SERVICE Product Change--Parcel Select and Parcel Return Service Negotiated Service... United States Postal Service[supreg] hereby gives notice that, pursuant to 39 U.S.C. 3642 and 3632(b)(3... Postal Service to Add Parcel Select & Parcel Return Service Contract 4 to Competitive Product List...

  2. 78 FR 63521 - Product Change-Parcel Select & Parcel Return Service Negotiated Service Agreement

    Science.gov (United States)

    2013-10-24

    ... Request of the United States Postal Service to Add Parcel Select & Parcel Return Service Contract 5 to... POSTAL SERVICE Product Change--Parcel Select & Parcel Return Service Negotiated Service Agreement.... SUPPLEMENTARY INFORMATION: The United States Postal Service[supreg] hereby gives notice that, pursuant to 39 U.S...

  3. Puerto Rican Migration: The Return Flow = La Migracion Puertorriquena: El Reflujo a la Isla.

    Science.gov (United States)

    Vivo, Paquita, Comp.

    This is a guide to materials and research on Puerto Ricans who have returned to Puerto Rico after living in the United States. Part 1 is an annotated bibliography of books, journal articles, printed documents, doctoral dissertations, master's theses, journalistic accounts, and unpublished papers on characteristics of Puerto Rican return migrants;…

  4. Returning home to die: Circular labour migration and mortality in South Africa1

    Science.gov (United States)

    CLARK, SAMUEL J.; COLLINSON, MARK A.; KAHN, KATHLEEN; DRULLINGER, KYLE; TOLLMAN, STEPHEN M.

    2010-01-01

    Aim: To examine the hypothesis that circular labour migrants who become seriously ill while living away from home return to their rural homes to convalesce and possibly to die. Methods: Drawing on longitudinal data collected by the Agincourt health and demographic surveillance system in rural northeastern South Africa between 1995 and 2004, discrete time event history analysis is used to estimate the likelihood of dying for residents, short-term returning migrants, and long-term returning migrants controlling for sex, age, and historical period. Results: The annual odds of dying for short-term returning migrants are generally 1.1 to 1.9 times (depending on period, sex, and age) higher than those of residents and long-term returning migrants, and these differences are generally highly statistically significant. Further supporting the hypothesis is the fact that the proportion of HIV/TB deaths among short-term returning migrants increases dramatically as time progresses, and short-term returning migrants account for an increasing proportion of all HIV/TB deaths. Conclusions: This evidence strongly suggests that increasing numbers of circular labour migrants of prime working age are becoming ill in the urban areas where they work and coming home to be cared for and eventually to die in the rural areas where their families live. This shifts the burden of caring for them in their terminal illness to their families and the rural healthcare system with significant consequences for the distribution and allocation of health care resources. PMID:17676501

  5. ‘The migration crisis’ and the ‘return to Africa’-discussion

    DEFF Research Database (Denmark)

    Seeberg, Peter

    2017-01-01

    in the Arab Mediterranean in future negotiations related to migration between the EU and the states involved in the complex migratory movements in the Mediterranean region and beyond. The article concludes that it will be difficult to persuade the Arab Mediterranean states to cooperate without promises...... of significant financial aid, and that several EU member states probably – rather than going for the negotiation strategy – will apply an ostrich approach to the question of how to solve the recent migration crisis....

  6. Africa - Israel - Africa Return-migration experiences of African labour migrants

    OpenAIRE

    Galia Sabar

    2013-01-01

    This paper analyses homecoming experiences of African labour migrants who lived in Israel and returned home. Using qualitative research methodologies, I discerned what factors - material and non-material - determine the relative success of the return process. Focusing on these factors’ effects, I offer a new understanding of labour migrants’ homecoming experiences: those who are “content,” “readjusting,” or “lost. Following Ulrich Beck's (2006) analysis of cosmopolitanism, I suggest that thes...

  7. Population structure, migration, and diversifying selection in the Netherlands

    Science.gov (United States)

    Abdellaoui, Abdel; Hottenga, Jouke-Jan; Knijff, Peter de; Nivard, Michel G; Xiao, Xiangjun; Scheet, Paul; Brooks, Andrew; Ehli, Erik A; Hu, Yueshan; Davies, Gareth E; Hudziak, James J; Sullivan, Patrick F; van Beijsterveldt, Toos; Willemsen, Gonneke; de Geus, Eco J; Penninx, Brenda W J H; Boomsma, Dorret I

    2013-01-01

    Genetic variation in a population can be summarized through principal component analysis (PCA) on genome-wide data. PCs derived from such analyses are valuable for genetic association studies, where they can correct for population stratification. We investigated how to capture the genetic population structure in a well-characterized sample from the Netherlands and in a worldwide data set and examined whether (1) removing long-range linkage disequilibrium (LD) regions and LD-based SNP pruning significantly improves correlations between PCs and geography and (2) whether genetic differentiation may have been influenced by migration and/or selection. In the Netherlands, three PCs showed significant correlations with geography, distinguishing between: (1) North and South; (2) East and West; and (3) the middle-band and the rest of the country. The third PC only emerged with minimized LD, which also significantly increased correlations with geography for the other two PCs. In addition to geography, the Dutch North–South PC showed correlations with genome-wide homozygosity (r=0.245), which may reflect a serial-founder effect due to northwards migration, and also with height (♂: r=0.142, ♀: r=0.153). The divergence between subpopulations identified by PCs is partly driven by selection pressures. The first three PCs showed significant signals for diversifying selection (545 SNPs - the majority within 184 genes). The strongest signal was observed between North and South for the functional SNP in HERC2 that determines human blue/brown eye color. Thus, this study demonstrates how to increase ancestry signals in a relatively homogeneous population and how those signals can reveal evolutionary history. PMID:23531865

  8. The saga of the returnee: exploring the implication of involuntary return migration, for development. A case study of the reintegration process for ghanaian migrant workers from Libya

    OpenAIRE

    Mensah, Esi Akyere

    2012-01-01

    Master thesis in development management- University of Agder, 2012 This thesis presents findings from a study that investigated the reintegration experiences of the returned Ghanaian migrants from Libya. The study, which was conducted in four communities employed qualitative methods to uncover the many complexities of involuntary return and its implications for development in southern countries; an under-researched area in the migration-return nexus. The findings highlight the effect o...

  9. Role of disease and demographic factors as determinants of return migration

    DEFF Research Database (Denmark)

    Handlos, Line Neerup; Petersen, Jorgen Holm; Bygbjerg, Ib Christian

    2017-01-01

    AIMS: A number of aspects of the health status of migrants who return to their country of origin have been explored in the literature; however, a more general description of the incidence of disease and demographic characteristics is lacking. The aim of this research was to contribute such a desc......AIMS: A number of aspects of the health status of migrants who return to their country of origin have been explored in the literature; however, a more general description of the incidence of disease and demographic characteristics is lacking. The aim of this research was to contribute...

  10. Portfolios with fuzzy returns: Selection strategies based on semi-infinite programming

    Science.gov (United States)

    Vercher, Enriqueta

    2008-08-01

    This paper provides new models for portfolio selection in which the returns on securities are considered fuzzy numbers rather than random variables. The investor's problem is to find the portfolio that minimizes the risk of achieving a return that is not less than the return of a riskless asset. The corresponding optimal portfolio is derived using semi-infinite programming in a soft framework. The return on each asset and their membership functions are described using historical data. The investment risk is approximated by mean intervals which evaluate the downside risk for a given fuzzy portfolio. This approach is illustrated with a numerical example.

  11. Networks and Selection in International Migration to Spain

    DEFF Research Database (Denmark)

    Neubecker, Nina; Smolka, Marcel; Steinbacher, Anne

    This paper provides new evidence on migrant networks as determinants of the scale and skill structure of migration, using aggregate data from a recent migration boom to Spain. We develop a three-level nested multinomial logit migration model. Our model accommodates varying degrees of similarity...

  12. Omega-optimized portfolios: applying stochastic dominance criterion for the selection of the threshold return

    Directory of Open Access Journals (Sweden)

    Renaldas Vilkancas

    2016-05-01

    Full Text Available Purpose of the article: While using asymmetric risk-return measures an important role is played by selection of the investor‘s required or threshold rate of return. The scientific literature usually states that every investor should define this rate according to their degree of risk aversion. In this paper, it is attempted to look at the problem from a different perspective – empirical research is aimed at determining the influence of the threshold rate of return on the portfolio characteristics. Methodology/methods: In order to determine the threshold rate of return a stochastic dominance criterion was used. The results are verified using the commonly applied method of backtesting. Scientific aim: The aim of this paper is to propose a method allowing selecting the threshold rate of return reliably and objectively. Findings: Empirical research confirms that stochastic dominance criteria can be successfully applied to determine the rate of return preferred by the investor. Conclusions: A risk-free investment rate or simply a zero rate of return commonly used in practice is often justified neither by theoretical nor empirical studies. This work suggests determining the threshold rate of return by applying the stochastic dominance criterion

  13. El retorno de las migraciones circulares: la regulación de las migraciones profesionales (The return of circular migration: regulation of professional migration

    Directory of Open Access Journals (Sweden)

    Santacreu Fernández, Óscar Antonio

    2009-06-01

    migratorio excluye otro tipo de migración especialmente importante: la no económica, donde la migración viene motivada por buscar nuevos horizontes vitales, explorar estilos de vida alternativos, persecución política, etc.Abstract: Again, the notion of circular migration as a process of rationalization of migrations with job motivation is reappearing. It is a concept that produces both favourable and adverse reactions among researchers. Like so many proposals, their strengths and weaknesses depend more on how is realized its regulation and its practical application than on their content and potential. A substantial part of migration corresponds to socio-economic reasons, associated with job mobility. For this type of migration, the break with the cultural elements of everyday life and the social networks from their home country are unintended consequences of mobility. The most visible contribution of their efforts in the countries of origin is the economic remittances. Circular migration suggests that mobility incorporates the notion of return. In other words, that migration involves a moment of their life cycle, where the return to their social environment of origin can become a reality, including benefits for a new migration later. The consequences of this restructuring on the horizon of life of the migrants are important. It allows reintegrate skilled human capital to the societies of origin, with positive consequences for social and economic development in these societies. It maintains the quality of emotional life for the migrants and their families. It intensifies the relationship between the societies and simplifies the problems of coexistence of contradictory religious or cultural systems, with particular reference to freedom and equality. There are numerous examples relating to gender violence, children, etc, that are unacceptable in the democratic Western societies. Certainly the optimal scope is defined by economic migration. This migratory approach excludes

  14. Economic opportunity in Mexico and return migration from the United States.

    Science.gov (United States)

    Lindstrom, D P

    1996-08-01

    I analyze the influence of the economic characteristics of origin area on trip duration for Mexican migrants in the United States. I argue that migrants from economically dynamic areas in Mexico with favorable opportunities for employment and small capital investment have a larger incentive to stay in the United States longer and to withstand the psychic costs of separation from family and friends than do migrants from economically stagnant areas in Mexico, where the productive uses of savings are severely limited. In line with this argument we should expect investment opportunities in migrants' origin areas to be associated positively with migrants' trip duration in the United States. To test this hypothesis I use individual- and household-level data on U.S. migration experience collected in 13 Mexican communities. Evidence from parametric hazards models supports the idea that economic characteristics of origin areas influence the motivations and strategies of Mexican migrants in the United States.

  15. Representation Bias, Return Forecast, and Portfolio Selection in the Stock Market of China

    Directory of Open Access Journals (Sweden)

    Daping Zhao

    2014-01-01

    Full Text Available Representation bias means a kind of cognitive tendency, and, for investors, it can affect their behavior in the stock market. Whether the representation bias can help the return forecast and portfolio selection is an interesting problem that is less studied. In this paper, based on the representation bias theory and current markets situation in China, a new hierarchy of stock measurement system is constructed and a corresponding set of criteria is also proposed. On each criterion, we try to measure the influence among stocks with adapted fuzzy AHP. Then the Hausdorff distance is applied to weight and compute the horizontal representation returns. For the forecast returns, according to representation behaviors, there is also a new computation method. Empirical results show that the representation bias information is useful to the return forecast as well as the portfolio selection.

  16. Who Benefits Most from College? Evidence for Negative Selection in Heterogeneous Economic Returns to Higher Education

    Science.gov (United States)

    Brand, Jennie E.; Yu Xie,

    2010-01-01

    In this article, we consider how the economic return to a college education varies across members of the U.S. population. Based on principles of comparative advantage, scholars commonly presume that positive selection is at work, that is, individuals who are most likely to select into college also benefit most from college. Net of observed…

  17. Equilibrium and nonequilibrium attractors for a discrete, selection-migration model

    Science.gov (United States)

    James F. Selgrade; James H. Roberds

    2003-01-01

    This study presents a discrete-time model for the effects of selection and immigration on the demographic and genetic compositions of a population. Under biologically reasonable conditions, it is shown that the model always has an equilibrium. Although equilibria for similar models without migration must have real eigenvalues, for this selection-migration model we...

  18. Migration and development in Pakistan: some selected issues.

    Science.gov (United States)

    Irfan, M

    1986-01-01

    Various sources of cross-sectional data were used as a basis for considering some of the interrelationships between migration and development in Pakistan, particularly the effects on the labor-exporting rural areas. The available data yield a range of estimates as to the level of mobility. During the 1970s, around 7-10% of Pakistan's population changed residence. The incidence of migration was higher among females than males. Women's greater propensity to migrate can be attributed primarily to patrilocal marriage customs wherein a significant proportion of females migrate, particularly in the rural areas. According to the 1979 Population, Labor Force and Migration Survey, the share of migrants in the total female population fell from 11.8% to 4.8% when migration for marriage is excluded. In Pakistan, mobility is predominantly local or involves short distances only. Only 19% of the internal migrants crossed provincial boundaries. 29.8% of the flow was from rural to urban areas. The remainder of the volume of internal migration was shared equally by inter-city and urban-to-rural migrants. The coincidence of the timing of marriage and entry into the labor market in individuals' life cycles generated a peak for the 15-24 age group in the age-mobility curve. A positive association exists between education and the propensity to migrate. In terms of origin, the propensity to move exhibited by the higher educational group was higher (33%) in rural areas than in urban areas (10%). 83% of this group from rural areas moved to urban centers; 80% of the same educational background chose another urban center as destination. The data on remittances may suffer both from reporting areas and being unrepresentative. The remittances estimated due to internal migration, on the basis of the PLM survey, amounted to 3 billion rupees in 1978. On average, remittances accounted for 35% of the earnings of the migrants. Average remittances were substantially less than the earnings of

  19. Uniqueness of polymorphism for a discrete, selection-migration model with genetic dominance

    Science.gov (United States)

    James F. Selgrade; James H. Roberds

    2009-01-01

    The migration into a natural population of a controlled population, e.g., a transgenic population, is studied using a one island selection-migration model. A 2-dimensional system of nonlinear difference equations describes changes in allele frequency and population size between generations. Biologically reasonable conditions are obtained which guarantee the existence...

  20. The Effect of Exit Strategy on Optimal Portfolio Selection with Birandom Returns

    Directory of Open Access Journals (Sweden)

    Guohua Cao

    2013-01-01

    Full Text Available The aims of this paper are to use a birandom variable to denote the stock return selected by some recurring technical patterns and to study the effect of exit strategy on optimal portfolio selection with birandom returns. Firstly, we propose a new method to estimate the stock return and use birandom distribution to denote the final stock return which can reflect the features of technical patterns and investors' heterogeneity simultaneously; secondly, we build a birandom safety-first model and design a hybrid intelligent algorithm to help investors make decisions; finally, we innovatively study the effect of exit strategy on the given birandom safety-first model. The results indicate that (1 the exit strategy affects the proportion of portfolio, (2 the performance of taking the exit strategy is better than when the exit strategy is not taken, if the stop-loss point and the stop-profit point are appropriately set, and (3 the investor using the exit strategy become conservative.

  1. Migration of selected radionuclides in the food chain. II

    International Nuclear Information System (INIS)

    Hanusik, V.; Smajda, B.; Musatovova, O.; Szabova, T.

    1983-01-01

    The migration is described of radiostrontium, radiocesium and radioiodine in the system plant-animal-man, and the impact is monitored of the individual factors on the accumulation of these radionuclides in the organisms of animals and humans. On the basis of data published (NRC Regulatory Guide 1.109) relating to the variability of the parameters of the model, the range is estimated of variations of radiostrontium and radiocesium concentrations in meat and in milk as is the range of variations of the whole-body dose equivalent. (author)

  2. Migration characterization of Ga and In adatoms on dielectric surface in selective MOVPE

    International Nuclear Information System (INIS)

    Chen Wei-Jie; Han Xiao-Biao; Lin Jia-Li; Hu Guo-Heng; Liu Ming-Gang; Yang Yi-Bin; Chen Jie; Wu Zhi-Sheng; Zhang Bai-Jun; Liu Yang

    2015-01-01

    Migration characterizations of Ga and In adatoms on the dielectric surface in selective metal organic vapor phase epitaxy (MOVPE) were investigated. In the typical MOVPE environment, the selectivity of growth is preserved for GaN, and the growth rate of GaN micro-pyramids is sensitive to the period of the patterned SiO 2 mask. A surface migration induced model was adopted to figure out the effective migration length of Ga adatoms on the dielectric surface. Different from the growth of GaN, the selective area growth of InGaN on the patterned template would induce the deposition of InGaN polycrystalline particles on the patterned SiO 2 mask with a long period. It was demonstrated with a scanning electron microscope and energy dispersive spectroscopy that the In adatoms exhibit a shorter migration length on the dielectric surface. (paper)

  3. Global migration and the selective reimagining of religions

    Directory of Open Access Journals (Sweden)

    Peter Beyer

    1998-06-01

    Full Text Available Abstract It is a commonplace in discussions of immigrant religion to speak of how religion aids in the adjustment of migrants to a new culture and society; how it serves as a dimension of continuity in the process of integration. This article examines theoretical foundations for reconsidering this perspective in the context of globalization in general and global migration in particular. In a global society, it is far less useful to think of migrants as leaving one society to join another, especially insofar as this optic tends to assume a that the new “host” culture remains comparatively unaffected while the immigrants culture faces the dilemma of assimilation versus ethnic preservation; and b that the culture of origin simply loses a few members without much effect by the migrants back onto their cultures of origin. By contrast, the article argues that the consequences of migration are to help (redefine religions in all areas where they are represented; and thus to make distinctions between “core” and “diaspora” far less salient. Instead, different areas where religious traditions are represented are better seen as centres for creating different options for the authentic construction of the same religion; options that are very often in communication with each other.

  4. A hybrid intelligent algorithm for portfolio selection problem with fuzzy returns

    Science.gov (United States)

    Li, Xiang; Zhang, Yang; Wong, Hau-San; Qin, Zhongfeng

    2009-11-01

    Portfolio selection theory with fuzzy returns has been well developed and widely applied. Within the framework of credibility theory, several fuzzy portfolio selection models have been proposed such as mean-variance model, entropy optimization model, chance constrained programming model and so on. In order to solve these nonlinear optimization models, a hybrid intelligent algorithm is designed by integrating simulated annealing algorithm, neural network and fuzzy simulation techniques, where the neural network is used to approximate the expected value and variance for fuzzy returns and the fuzzy simulation is used to generate the training data for neural network. Since these models are used to be solved by genetic algorithm, some comparisons between the hybrid intelligent algorithm and genetic algorithm are given in terms of numerical examples, which imply that the hybrid intelligent algorithm is robust and more effective. In particular, it reduces the running time significantly for large size problems.

  5. Selective Modulation of Integrin-mediated Cell Migration by Distinct ADAM Family MembersV⃞

    Science.gov (United States)

    Huang, Jing; Bridges, Lance C.; White, Judith M.

    2005-01-01

    A disintegrin and a metalloprotease (ADAM) family members have been implicated in many biological processes. Although it is recognized that recombinant ADAM disintegrin domains can interact with integrins, little is known about ADAM-integrin interactions in cellular context. Here, we tested whether ADAMs can selectively regulate integrin-mediated cell migration. ADAMs were expressed in Chinese hamster ovary cells that express defined integrins (α4β1, α5β1, or both), and cell migration on full-length fibronectin or on its α4β1 or α5β1 binding fragments was studied. We found that ADAMs inhibit integrin-mediated cell migration in patterns dictated by the integrin binding profiles of their isolated disintegrin domains. ADAM12 inhibited cell migration mediated by the α4β1 but not the α5β1 integrin. ADAM17 had the reciprocal effect; it inhibited α5β1- but not α4β1-mediated cell migration. ADAM19 and ADAM33 inhibited migration mediated by both α4β1 and α5β1 integrins. A point mutation in the ADAM12 disintegrin loop partially reduced the inhibitory effect of ADAM12 on cell migration on the α4β1 binding fragment of fibronectin, whereas mutations that block metalloprotease activity had no effect. Our results indicate that distinct ADAMs can modulate cell migration mediated by specific integrins in a pattern dictated, at least in part, by their disintegrin domains. PMID:16079176

  6. Selection and network effects - Migration flows into OECD countries 1990-2000

    DEFF Research Database (Denmark)

    Pedersen, Peder J.; Pytlikova, Mariola; Smith, Nina

    2008-01-01

    This paper presents empirical evidence on immigration flows into the OECD countries during the period 1990-2000. Our results indicate that network effects are strong, but vary between different groups of welfare states and between countries according to the type of immigration policy being applie...... a major influence on the observed migration patterns until now. This may partly be explained by restrictive migration policies which may have dampened the potential selection effects....

  7. Selective Inhibitory Effect of Epigallocatechin-3-gallate on Migration of Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Jong-Chul Park

    2010-11-01

    Full Text Available In order to prevent restenosis after angioplasty or stenting, one of the most popular targets is suppression of the abnormal growth and excess migration of vascular smooth muscle cells (VSMCs with drugs. However, the drugs also adversely affect vascular endothelial cells (VECs, leading to the induction of late thrombosis. We have investigated the effect of epigallocatechin-3-gallate (EGCG on the proliferation and migration of VECs and VSMCs. Both cells showed dose-dependent decrease of viability in response to EGCG while they have different IC50 values of EGCG (VECs, 150 mM and VSMCs, 1050 mM. Incubating both cells with EGCG resulted in significant reduction in cell proliferation irrespective of cell type. The proliferation of VECs were greater affected than that of VSMCs at the same concentrations of EGCG. EGCG exerted differential migration-inhibitory activity in VECs vs. VSMCs. The migration of VECs was not attenuated by 200 mM EGCG, but that of VSMCs was significantly inhibited at the same concentration of EGCG. It is suggested that that EGCG can be effectively used as an efficient drug for vascular diseases or stents due to its selective activity, completely suppressing the proliferation and migration of VSMCs, but not adversely affecting VECs migration in blood vessels.

  8. Dynamical behaviour of a discrete selection-migration model with arbitrary dominance

    Science.gov (United States)

    James F. Selgrade; Jordan West Bostic; James H. Roberds

    2009-01-01

    To study the effects of immigration of genes (possibly transgenic) into a natural population, a one-island selection-migration model with density-dependent regulation is used to track allele frequency and population size. The existence and uniqueness of a polymorphic genetic equilibrium is proved under a general assumption about dominance in fitnesses. Also, conditions...

  9. Urban-rural variations in health in the Netherlands: does selective migration play a part?

    NARCIS (Netherlands)

    Verheij, R.A.; Mheen, H.D. van de; Bakker, D.H. de; Groenewegen, P.P.; Mackenbach, J.P.

    1998-01-01

    Study objective: urban-rural health differences are observed in many countries, even when socioeconomic and demographic characteristics are controlled for. People living in urban areas are often found to be less healthy. One of the possible causes for these differences is selective migration with

  10. Dynamical Analysis of Density-dependent Selection in a Discrete one-island Migration Model

    Science.gov (United States)

    James H. Roberds; James F. Selgrade

    2000-01-01

    A system of non-linear difference equations is used to model the effects of density-dependent selection and migration in a population characterized by two alleles at a single gene locus. Results for the existence and stability of polymorphic equilibria are established. Properties for a genetically important class of equilibria associated with complete dominance in...

  11. A panel study of migration, self-selection and household real income.

    Science.gov (United States)

    Axelsson, R; Westerlund, O

    1998-02-01

    "The impact of migration on income for Swedish multi-adult households is examined using panel data pertaining to a sample of stable household constellations during the period 1980-1990. In contrast to previous studies, data on household disposable income is employed in estimating the income function. The empirical results indicate no significant effect on real disposable income from migration. In addition, the hypothesis of no self-selection, or zero correlation between the errors in the decision function and the income function, cannot be rejected." excerpt

  12. Least-squares reverse time migration of marine data with frequency-selection encoding

    KAUST Repository

    Dai, Wei

    2013-06-24

    The phase-encoding technique can sometimes increase the efficiency of the least-squares reverse time migration (LSRTM) by more than one order of magnitude. However, traditional random encoding functions require all the encoded shots to share the same receiver locations, thus limiting the usage to seismic surveys with a fixed spread geometry. We implement a frequency-selection encoding strategy that accommodates data with a marine streamer geometry. The encoding functions are delta functions in the frequency domain, so that all the encoded shots have unique nonoverlapping frequency content, and the receivers can distinguish the wavefield from each shot with a unique frequency band. Because the encoding functions are orthogonal to each other, there will be no crosstalk between different shots during modeling and migration. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is comparable to conventional RTM for the Marmousi2 model and a marine data set recorded in the Gulf of Mexico. With more iterations, the LSRTM image quality is further improved by suppressing migration artifacts, balancing reflector amplitudes, and enhancing the spatial resolution. We conclude that LSRTM with frequency-selection is an efficient migration method that can sometimes produce more focused images than conventional RTM. © 2013 Society of Exploration Geophysicists.

  13. Examining speed versus selection in connectivity models using elk migration as an example

    Science.gov (United States)

    Brennan, Angela; Hanks, Ephraim M.; Merkle, Jerod A.; Cole, Eric K.; Dewey, Sarah R.; Courtemanch, Alyson B.; Cross, Paul C.

    2018-01-01

    ContextLandscape resistance is vital to connectivity modeling and frequently derived from resource selection functions (RSFs). RSFs estimate relative probability of use and tend to focus on understanding habitat preferences during slow, routine animal movements (e.g., foraging). Dispersal and migration, however, can produce rarer, faster movements, in which case models of movement speed rather than resource selection may be more realistic for identifying habitats that facilitate connectivity.ObjectiveTo compare two connectivity modeling approaches applied to resistance estimated from models of movement rate and resource selection.MethodsUsing movement data from migrating elk, we evaluated continuous time Markov chain (CTMC) and movement-based RSF models (i.e., step selection functions [SSFs]). We applied circuit theory and shortest random path (SRP) algorithms to CTMC, SSF and null (i.e., flat) resistance surfaces to predict corridors between elk seasonal ranges. We evaluated prediction accuracy by comparing model predictions to empirical elk movements.ResultsAll connectivity models predicted elk movements well, but models applied to CTMC resistance were more accurate than models applied to SSF and null resistance. Circuit theory models were more accurate on average than SRP models.ConclusionsCTMC can be more realistic than SSFs for estimating resistance for fast movements, though SSFs may demonstrate some predictive ability when animals also move slowly through corridors (e.g., stopover use during migration). High null model accuracy suggests seasonal range data may also be critical for predicting direct migration routes. For animals that migrate or disperse across large landscapes, we recommend incorporating CTMC into the connectivity modeling toolkit.

  14. 'Insane emigrants' in transit: Psychiatric patients' files as a source for the history of return migration, c. 1910

    NARCIS (Netherlands)

    Blok, G.

    2015-01-01

    This article highlights a source that can contribute to the history of migration and mental health: the case records of Eastern European emigrants who tried to enter America at the beginning of the twentieth century, but were refused entrance because of their alleged insanity. Some of these

  15. A Location Selection Policy of Live Virtual Machine Migration for Power Saving and Load Balancing

    Directory of Open Access Journals (Sweden)

    Jia Zhao

    2013-01-01

    Full Text Available Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy of live VM migration for power saving and load balancing. We propose a novel approach MOGA-LS, which is a heuristic and self-adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA. This paper has presented the specific design and implementation of MOGA-LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA idea into MOGA-LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long-term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA-LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high-effective and meaningful.

  16. A location selection policy of live virtual machine migration for power saving and load balancing.

    Science.gov (United States)

    Zhao, Jia; Ding, Yan; Xu, Gaochao; Hu, Liang; Dong, Yushuang; Fu, Xiaodong

    2013-01-01

    Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy) of live VM migration for power saving and load balancing. We propose a novel approach MOGA-LS, which is a heuristic and self-adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA). This paper has presented the specific design and implementation of MOGA-LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA) idea into MOGA-LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long-term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA-LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high-effective and meaningful.

  17. Least-squares reverse time migration of marine data with frequency-selection encoding

    KAUST Repository

    Dai, Wei

    2013-08-20

    The phase-encoding technique can sometimes increase the efficiency of the least-squares reverse time migration (LSRTM) by more than one order of magnitude. However, traditional random encoding functions require all the encoded shots to share the same receiver locations, thus limiting the usage to seismic surveys with a fixed spread geometry. We implement a frequency-selection encoding strategy that accommodates data with a marine streamer geometry. The encoding functions are delta functions in the frequency domain, so that all the en- coded shots have unique non-overlapping frequency content, and the receivers can distinguish the wavefield from each shot with a unique frequency band. Since the encoding functions are orthogonal to each other, there will be no crosstalk between different shots during modeling and migration. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is compara- ble to conventional RTM for both the Marmousi2 model and a marine data set recorded in the Gulf of Mexico. With more iterations, the LSRTM image quality is further improved. We conclude that LSRTM with frequency-selection is an efficient migration method that can sometimes produce more focused images than conventional RTM.

  18. Sexual selection predicts advancement of avian spring migration in response to climate change

    DEFF Research Database (Denmark)

    Spottiswoode, Claire N; Tøttrup, Anders P; Coppack, Timothy

    2006-01-01

    Global warming has led to earlier spring arrival of migratory birds, but the extent of this advancement varies greatly among species, and it remains uncertain to what degree these changes are phenotypically plastic responses or microevolutionary adaptations to changing environmental conditions. We...... suggest that sexual selection could help to understand this variation, since early spring arrival of males is favoured by female choice. Climate change could weaken the strength of natural selection opposing sexual selection for early migration, which would predict greatest advancement in species...... in the timing of first-arriving individuals, suggesting that selection has not only acted on protandrous males. These results suggest that sexual selection may have an impact on the responses of organisms to climate change, and knowledge of a species' mating system might help to inform attempts at predicting...

  19. Educational Selectivity of Out-migration in Canada: 1976-1981 to 1996-2001

    Directory of Open Access Journals (Sweden)

    Bali Ram

    2007-12-01

    Full Text Available The major objective of this paper is to show that migrants are positively selected whether they are driven by economic factors or by non-economic factors, and whether they are motivated by pull factors or push factors. Using “five-year migration data” from the 1981 to 2001 censuses of Canada, we find that the education gradient of out-migration is apparent in every region, with the highly educated being more mobile than the less educated. However, the pattern is most pronounced in the Atlantic region, Quebec, and Manitoba/Saskatchewan, the regions experiencing poorer economic conditions and persistent net losses through migration. The three high-income provinces, Ontario, Alberta, and British Columbia not only experience lower overall net losses, but are also less likely to lose their better educated persons—even during bad economic times. Quebec emerges as a special case where economic as well as linguistic-political factors play an important role in governing the out-migration patterns of the better educated, particularly those belonging to the non-Francophone group.

  20. Could hypomanic traits explain selective migration? Verifying the hypothesis by the surveys on sardinian migrants.

    Science.gov (United States)

    Giovanni, Carta Mauro; Francesca, Moro Maria; Viviane, Kovess; Brasesco, Maria Veronica; Bhat, Krishna M; Matthias, Angermeyer C; Akiskal, Hagop S

    2012-01-01

    A recent survey put forward the hypothesis that the emigration that occurred from Sardinia from the 1960's to the 1980's, selected people with a hypomanic temperament. The paper aims to verify if the people who migrated from Sardinia in that period have shown a high risk of mood disorders in the surveys carried out in their host countries, and if the results are consistent with this hypothesis. This is systematic review. In the 1970's when examining the attitudes towards migration in Sardinian couples waiting to emigrate, Rudas found that the decision to emigrate was principally taken by males. Female showed lower self-esteem than male emigrants. A study on Sardinian immigrants in Argentina carried out in 2001-02, at the peak of the economic crisis, found a high risk of depressive disorders in women only. These results were opposite to the findings recorded ten years earlier in a survey on Sardinian immigrants in Paris, where the risk of Depressive Episode was higher in young men only. Data point to a bipolar disorder risk for young (probably hypomanic) male migrants in competitive, challenging conditions; and a different kind of depressive episodes for women in trying economic conditions. The results of the survey on Sardinian migrants are partially in agreement with the hypothesis of a selective migration of people with a hypomanic temperament. Early motivations and self-esteem seem related to the ways mood disorders are expressed, and to the vulnerability to specific triggering situations in the host country.

  1. Hemispheric-scale wind selection facilitates bar-tailed godwit circum-migration of the Pacific

    Science.gov (United States)

    Gill, Robert E.; Douglas, David C.; Handel, Colleen M.; Tibbitts, T. Lee; Hufford, Gary; Piersma, Theunis

    2014-01-01

    The annual 29 000 km long migration of the bar-tailed godwit, Limosa lapponica baueri, around the Pacific Ocean traverses what is arguably the most complex and seasonally structured atmospheric setting on Earth. Faced with marked variation in wind regimes and storm conditions across oceanic migration corridors, individuals must make critical decisions about when and where to fly during nonstop flights of a week's duration or longer. At a minimum, their decisions will affect wind profitability and thus reduce energetic costs of migration; in the extreme, poor decisions or unpredictable weather events will risk survival. We used satellite telemetry to track the annual migration of 24 bar-tailed godwits and analysed their flight performance relative to wind conditions during three major migration legs between nonbreeding grounds in New Zealand and breeding grounds in Alaska. Because flight altitudes of birds en route were unknown, we modelled flight efficiency at six geopotential heights across each migratory segment. Birds selected departure dates when atmospheric conditions conferred the greatest wind assistance both at departure and throughout their flights. This behaviour suggests that there exists a cognitive mechanism, heretofore unknown among migratory birds, that allows godwits to assess changes in weather conditions that are linked (i.e. teleconnected) across widely separated atmospheric regions. Godwits also showed adaptive flexibility in their response not only to cues related to seasonal changes in macrometeorology, such as spatial shifting of storm tracks and temporal periods of cyclogenesis, but also to cues associated with stochastic events, especially at departure sites. Godwits showed limits to their response behaviours, however, especially relative to rapidly developing stochastic events while en route. We found that flight efficiency depended significantly upon altitude and hypothesize that godwits exhibit further adaptive flexibility by varying

  2. A Heuristic Placement Selection of Live Virtual Machine Migration for Energy-Saving in Cloud Computing Environment

    Science.gov (United States)

    Zhao, Jia; Hu, Liang; Ding, Yan; Xu, Gaochao; Hu, Ming

    2014-01-01

    The field of live VM (virtual machine) migration has been a hotspot problem in green cloud computing. Live VM migration problem is divided into two research aspects: live VM migration mechanism and live VM migration policy. In the meanwhile, with the development of energy-aware computing, we have focused on the VM placement selection of live migration, namely live VM migration policy for energy saving. In this paper, a novel heuristic approach PS-ES is presented. Its main idea includes two parts. One is that it combines the PSO (particle swarm optimization) idea with the SA (simulated annealing) idea to achieve an improved PSO-based approach with the better global search's ability. The other one is that it uses the Probability Theory and Mathematical Statistics and once again utilizes the SA idea to deal with the data obtained from the improved PSO-based process to get the final solution. And thus the whole approach achieves a long-term optimization for energy saving as it has considered not only the optimization of the current problem scenario but also that of the future problem. The experimental results demonstrate that PS-ES evidently reduces the total incremental energy consumption and better protects the performance of VM running and migrating compared with randomly migrating and optimally migrating. As a result, the proposed PS-ES approach has capabilities to make the result of live VM migration events more high-effective and valuable. PMID:25251339

  3. A heuristic placement selection of live virtual machine migration for energy-saving in cloud computing environment.

    Science.gov (United States)

    Zhao, Jia; Hu, Liang; Ding, Yan; Xu, Gaochao; Hu, Ming

    2014-01-01

    The field of live VM (virtual machine) migration has been a hotspot problem in green cloud computing. Live VM migration problem is divided into two research aspects: live VM migration mechanism and live VM migration policy. In the meanwhile, with the development of energy-aware computing, we have focused on the VM placement selection of live migration, namely live VM migration policy for energy saving. In this paper, a novel heuristic approach PS-ES is presented. Its main idea includes two parts. One is that it combines the PSO (particle swarm optimization) idea with the SA (simulated annealing) idea to achieve an improved PSO-based approach with the better global search's ability. The other one is that it uses the Probability Theory and Mathematical Statistics and once again utilizes the SA idea to deal with the data obtained from the improved PSO-based process to get the final solution. And thus the whole approach achieves a long-term optimization for energy saving as it has considered not only the optimization of the current problem scenario but also that of the future problem. The experimental results demonstrate that PS-ES evidently reduces the total incremental energy consumption and better protects the performance of VM running and migrating compared with randomly migrating and optimally migrating. As a result, the proposed PS-ES approach has capabilities to make the result of live VM migration events more high-effective and valuable.

  4. A heuristic placement selection of live virtual machine migration for energy-saving in cloud computing environment.

    Directory of Open Access Journals (Sweden)

    Jia Zhao

    Full Text Available The field of live VM (virtual machine migration has been a hotspot problem in green cloud computing. Live VM migration problem is divided into two research aspects: live VM migration mechanism and live VM migration policy. In the meanwhile, with the development of energy-aware computing, we have focused on the VM placement selection of live migration, namely live VM migration policy for energy saving. In this paper, a novel heuristic approach PS-ES is presented. Its main idea includes two parts. One is that it combines the PSO (particle swarm optimization idea with the SA (simulated annealing idea to achieve an improved PSO-based approach with the better global search's ability. The other one is that it uses the Probability Theory and Mathematical Statistics and once again utilizes the SA idea to deal with the data obtained from the improved PSO-based process to get the final solution. And thus the whole approach achieves a long-term optimization for energy saving as it has considered not only the optimization of the current problem scenario but also that of the future problem. The experimental results demonstrate that PS-ES evidently reduces the total incremental energy consumption and better protects the performance of VM running and migrating compared with randomly migrating and optimally migrating. As a result, the proposed PS-ES approach has capabilities to make the result of live VM migration events more high-effective and valuable.

  5. Selective Expression of an Endogenous Inhibitor of FAK Regulates Proliferation and Migration of Vascular Smooth Muscle Cells

    Science.gov (United States)

    Taylor, Joan M.; Mack, Christopher P.; Nolan, Kate; Regan, Christopher P.; Owens, Gary K.; Parsons, J. Thomas

    2001-01-01

    Extracellular matrix signaling via integrin receptors is important for smooth muscle cell (SMC) differentiation during vasculogenesis and for phenotypic modulation of SMCs during atherosclerosis. We previously reported that the noncatalytic carboxyl-terminal protein binding domain of focal adhesion kinase (FAK) is expressed as a separate protein termed FAK-related nonkinase (FRNK) and that ectopic expression of FRNK can attenuate FAK activity and integrin-dependent signaling (A. Richardson and J. T. Parsons, Nature 380:538–540, 1996). Herein we report that in contrast to FAK, which is expressed ubiquitously, FRNK is expressed selectively in SMCs, with particularly high levels observed in conduit blood vessels. FRNK expression was low during embryonic development, was significantly upregulated in the postnatal period, and returned to low but detectable levels in adult tissues. FRNK expression was also dramatically upregulated following balloon-induced carotid artery injury. In cultured rat aortic smooth muscle cells, overexpression of FRNK attenuated platelet-derived growth factor (PDGF)-BB-induced migration and also dramatically inhibited [3H]thymidine incorporation upon stimulation with PDGF-BB or 10% serum. These effects were concomitant with a reduction in SMC proliferation. Taken together, these data indicate that FRNK acts as an endogenous inhibitor of FAK signaling in SMCs. Furthermore, increased FRNK expression following vascular injury or during development may alter the SMC phenotype by negatively regulating proliferative and migratory signals. PMID:11238893

  6. Cross sectional moments and portfolio returns: Evidence for select emerging markets

    Directory of Open Access Journals (Sweden)

    Sanjay Sehgal

    2016-09-01

    Full Text Available Research does not indicate a consensus on the relationship between idiosyncratic volatility and asset returns. Moreover, the role of cross sectional higher order moments in predicting market returns is relatively unexplored. We show that the cross sectional volatility measure suggested by Garcia et al. is highly correlated with alternative measures of idiosyncratic volatility constructed as variance of errors from the capital asset pricing model and the Fama French model. We find that cross sectional moments help in predicting aggregate market returns in some sample countries and also provide information for portfolio formation, which is more consistent for portfolios sorted on sensitivity to cross sectional skewness.

  7. Regulatory domain selectivity in the cell-type specific PKN-dependence of cell migration.

    Directory of Open Access Journals (Sweden)

    Sylvie Lachmann

    Full Text Available The mammalian protein kinase N (PKN family of Serine/Threonine kinases comprises three isoforms, which are targets for Rho family GTPases. Small GTPases are major regulators of the cellular cytoskeleton, generating interest in the role(s of specific PKN isoforms in processes such as cell migration and invasion. It has been reported that PKN3 is required for prostate tumour cell invasion but not PKN1 or 2. Here we employ a cell model, the 5637 bladder tumour cell line where PKN2 is relatively highly expressed, to assess the potential redundancy of these isoforms in migratory responses. It is established that PKN2 has a critical role in the migration and invasion of these cells. Furthermore, using a PKN wild-type and chimera rescue strategy, it is shown that PKN isoforms are not simply redundant in supporting migration, but appear to be linked through isoform specific regulatory domain properties to selective upstream signals. It is concluded that intervention in PKNs may need to be directed at multiple isoforms to be effective in different cell types.

  8. Regulatory domain selectivity in the cell-type specific PKN-dependence of cell migration.

    Science.gov (United States)

    Lachmann, Sylvie; Jevons, Amy; De Rycker, Manu; Casamassima, Adele; Radtke, Simone; Collazos, Alejandra; Parker, Peter J

    2011-01-01

    The mammalian protein kinase N (PKN) family of Serine/Threonine kinases comprises three isoforms, which are targets for Rho family GTPases. Small GTPases are major regulators of the cellular cytoskeleton, generating interest in the role(s) of specific PKN isoforms in processes such as cell migration and invasion. It has been reported that PKN3 is required for prostate tumour cell invasion but not PKN1 or 2. Here we employ a cell model, the 5637 bladder tumour cell line where PKN2 is relatively highly expressed, to assess the potential redundancy of these isoforms in migratory responses. It is established that PKN2 has a critical role in the migration and invasion of these cells. Furthermore, using a PKN wild-type and chimera rescue strategy, it is shown that PKN isoforms are not simply redundant in supporting migration, but appear to be linked through isoform specific regulatory domain properties to selective upstream signals. It is concluded that intervention in PKNs may need to be directed at multiple isoforms to be effective in different cell types.

  9. Management of and economic returns from selected fisheries in the Nordic Countries

    DEFF Research Database (Denmark)

    Nielsen, Max; Flaaten, Ola; Waldö, Staffan

    2012-01-01

    There is potential to increase the economic returns in many fisheries by improving fisheries management. In this article, maximum and estimated current resource rents are analyzed using a standardized methodology for five case studies of fisheries with different management regimes: individual quo...

  10. Multi-Period Mean-Variance Portfolio Selection with Uncertain Time Horizon When Returns Are Serially Correlated

    Directory of Open Access Journals (Sweden)

    Ling Zhang

    2012-01-01

    Full Text Available We study a multi-period mean-variance portfolio selection problem with an uncertain time horizon and serial correlations. Firstly, we embed the nonseparable multi-period optimization problem into a separable quadratic optimization problem with uncertain exit time by employing the embedding technique of Li and Ng (2000. Then we convert the later into an optimization problem with deterministic exit time. Finally, using the dynamic programming approach, we explicitly derive the optimal strategy and the efficient frontier for the dynamic mean-variance optimization problem. A numerical example with AR(1 return process is also presented, which shows that both the uncertainty of exit time and the serial correlations of returns have significant impacts on the optimal strategy and the efficient frontier.

  11. Returning home

    DEFF Research Database (Denmark)

    Agergaard, Jytte; Brøgger, Ditte

    2016-01-01

    flows. By focusing on these educational migrants, this paper explores how they connect to their rural homes. Guided by a critical reading of the migration-development scholarship, the paper examines how migrants and their relatives make sense of educational migrants’ remitting and returning practices......, and by comparing three groups of educational migrants, the migrants’ reasons for staying connected and sending remittances are scrutinized. The paper finds that although educational migrants do not generate extensive economic remittances for local development in Nepal, they stay connected to their rural homes...

  12. Least-squares Migration and Full Waveform Inversion with Multisource Frequency Selection

    KAUST Repository

    Huang, Yunsong

    2013-09-01

    Multisource Least-Squares Migration (LSM) of phase-encoded supergathers has shown great promise in reducing the computational cost of conventional migration. But for the marine acquisition geometry this approach faces the challenge of erroneous misfit due to the mismatch between the limited number of live traces/shot recorded in the field and the pervasive number of traces generated by the finite-difference modeling method. To tackle this mismatch problem, I present a frequency selection strategy with LSM of supergathers. The key idea is, at each LSM iteration, to assign a unique frequency band to each shot gather, so that the spectral overlap among those shots—and therefore their crosstallk—is zero. Consequently, each receiver can unambiguously identify and then discount the superfluous sources—those that are not associated with the receiver in marine acquisition. To compare with standard migration, I apply the proposed method to 2D SEG/EAGE salt model and obtain better resolved images computed at about 1/8 the cost; results for 3D SEG/EAGE salt model, with Ocean Bottom Seismometer (OBS) survey, show a speedup of 40×. This strategy is next extended to multisource Full Waveform Inversion (FWI) of supergathers for marine streamer data, with the same advantages of computational efficiency and storage savings. In the Finite-Difference Time-Domain (FDTD) method, to mitigate spectral leakage due to delayed onsets of sine waves detected at receivers, I double the simulation time and retain only the second half of the simulated records. To compare with standard FWI, I apply the proposed method to 2D velocity model of SEG/EAGE salt and to Gulf Of Mexico (GOM) field data, and obtain a speedup of about 4× and 8×. Formulas are then derived for the resolution limits of various constituent wavepaths pertaining to FWI: diving waves, primary reflections, diffractions, and multiple reflections. They suggest that inverting multiples can provide some low and intermediate

  13. Modelling of nuclide migration for support of the site selection for near surface repository in Lithuania

    International Nuclear Information System (INIS)

    Kilda, R.; Poskas, P.; Ragaisis, V.

    2006-01-01

    Construction of the near surface repository (NSR) for disposal of short-lived low-and intermediate-level waste (LILW) is planned in Lithuania. Reference design of the repository was prepared. Site selection process is going on. Environmental Impact Assessment (EIA) Program and Report were prepared and are under review by regulators. Releases of radionuclides to water pathway and potential human exposure after closure of the NSR have been assessed for support of the site selection for NSR installation. Two candidate sites were taken under consideration. The assessments have been performed following ISAM methodology recommended by IAEA for safety assessments of near surface disposal facilities. The conceptual design of NSR as well as peculiarities of geological and hydro-geological environment relevant to each candidate site is taken into account. The results of the analysis as part of EIA Report are presented in the paper. It is demonstrated that estimated impact of potential radionuclide migration for both candidate sites is below dose constrain established by regulations of Lithuania. (author)

  14. Size-selective sorting in bubble streaming flows: Particle migration on fast time scales

    Science.gov (United States)

    Thameem, Raqeeb; Rallabandi, Bhargav; Hilgenfeldt, Sascha

    2015-11-01

    Steady streaming from ultrasonically driven microbubbles is an increasingly popular technique in microfluidics because such devices are easily manufactured and generate powerful and highly controllable flows. Combining streaming and Poiseuille transport flows allows for passive size-sensitive sorting at particle sizes and selectivities much smaller than the bubble radius. The crucial particle deflection and separation takes place over very small times (milliseconds) and length scales (20-30 microns) and can be rationalized using a simplified geometric mechanism. A quantitative theoretical description is achieved through the application of recent results on three-dimensional streaming flow field contributions. To develop a more fundamental understanding of the particle dynamics, we use high-speed photography of trajectories in polydisperse particle suspensions, recording the particle motion on the time scale of the bubble oscillation. Our data reveal the dependence of particle displacement on driving phase, particle size, oscillatory flow speed, and streaming speed. With this information, the effective repulsive force exerted by the bubble on the particle can be quantified, showing for the first time how fast, selective particle migration is effected in a streaming flow. We acknowledge support by the National Science Foundation under grant number CBET-1236141.

  15. Movement pathways and habitat selection by woodland caribou during spring migration

    Directory of Open Access Journals (Sweden)

    D. Joanne Saher

    2005-05-01

    Full Text Available Woodland caribou (Rangifer tarandus caribou are a threatened species throughout Canada. Special management is therefore required to ensure habitat needs are met, particularly because much of their current distribution is heavily influenced by resource extraction activities. Although winter habitat is thought to be limiting and is the primary focus of conservation efforts, maintaining connectivity between summer and winter ranges has received little attention. We used global positioning system data from an interprovincial, woodland caribou herd to define migratory movements on a relatively pristine range. Non-linear models indicated that caribou movement during migration was punctuated; caribou traveled for some distance (movement phase followed by a pause (resting/foraging phase. We then developed resource selection functions (RSFs, using case-controlled logistic regression, to describe resting/foraging sites and movement sites, at the landscape scale. The RSFs indicated that caribou traveled through areas that were less rugged and closer to water than random and that resting/foraging sites were associated with older forests that have a greater component of pine, and are further from water than were random available locations. This approach to analyzing animal location data allowed us to identify two patterns of habitat selection (travel and foraging/resting for caribou during the migratory period. Resultant models are important tools for land use planning to ensure that connectivity between caribou summer and winter ranges is maintained.

  16. Breast cancer survivors: return to work and wage loss in selected hospitals in Malaysia.

    Science.gov (United States)

    Su, T T; Azzani, M; Tan, F L; Loh, S Y

    2018-05-01

    This study aimed, firstly, to assess the determinants of return to work (RTW), secondly, to explore the amount of annual wage loss, and finally, to discover the determinants of wage loss among breast cancer (BC) survivors. A cross-sectional study design was used in this research. The data was collected via interview using a validated questionnaire. Logistic regression models were developed to discover the significant determinants of RTW and of wage loss among BC survivors. A total of 256 BC survivors were included in this study. The analysis showed that there was a 21% loss of or reduction in mean income within 1 year after diagnosis. The significant predictors of RTW are being a government employee, having reduced wages or wage loss, and if the case had been diagnosed 1 year or more ago. Being a private sector employee and having a late stage of cancer was a barrier to RTW. The main risk factors for reduced wages or wage loss were belonging to the age group of 40-59 years, being of Chinese or Indian ethnicity, having low educational status, and not returning to work. However, belonging to the higher monthly income group (earning > RM 2000) is a protective factor against the risk of reduced wages or wage loss. Non-RTW and wage loss after diagnosis of BC may result in the survivors experiencing a significant financial burden. Assessment of these patients is becoming more crucial because more women participate in the workforce in Malaysia nowadays and because BC is managed using multiple treatment modalities with their consequences could lead to long absences from work.

  17. Migration within China and from China to the USA: the effects of migration networks, selectivity, and the rural political economy in Fujian Province.

    Science.gov (United States)

    Liang, Zai; Chunyu, Miao David

    2013-07-01

    This paper tests a new strategy for simultaneously studying internal migration within, and international migration from, China. Our theoretical discussion draws on ideas from migration-networks theory and studies of the transition to a market-oriented economy. Data collection is modelled on the Mexican Migration Project. We find that education is more important in initiating internal migration than international migration. Second, although the role of migration networks at a community level seems similar to that for Mexico-USA migration, the networks at a family level show a different pattern. Third, there is evidence that internal and international migration are competing options. Finally, we find that individuals with cadres (public officials) in the family are less likely to undertake internal migration, but more likely to participate in international migration, a finding that highlights the continuing significance of the cadres in coastal rural China.

  18. The modulation of inhibition of return by object-internal structure: implications for theories of object-based attentional selection.

    Science.gov (United States)

    Reppa, Irene; Leek, E Charles

    2003-06-01

    Recently, Vecera, Behrmann, and McGoldrick (2000), using a divided-attention task, reported that targets are detected more accurately when they occur on the same structural part of an object, suggesting that attention can be directed toward object-internal features. We present converging evidence using the object-based inhibition of return (IOR) paradigm as an implicit measure of selection. The results show that IOR is attenuated when cues and targets appear on the same part of an object relative to when they are separated by a part boundary. These findings suggest that object-based mechanisms of selection can operate over shape representations that make explicit information about object-internal structure.

  19. Does it pay to invest in Art? A Selection-corrected Returns Perspective

    NARCIS (Netherlands)

    A. Korteweg (Arthur); R. Kräussl (Roman); P. Verwijmeren (Patrick)

    2013-01-01

    markdownabstract__Abstract__ This paper shows the importance of correcting for sample selection when investing in illiquid assets with endogenous trading. Using a large sample of 20,538 paintings that were sold repeatedly at auction between 1972 and 2010, we find that paintings with higher price

  20. Human capital on the move: Education as a determinant of internal migration in selected INDEPTH surveillance populations in Africa

    Directory of Open Access Journals (Sweden)

    Carren Ginsburg

    2016-05-01

    Full Text Available Background: Education, as a key indicator of human capital, is considered one of the major determinants of internal migration, with previous studies suggesting that human capital accumulates in urban areas at the expense of rural areas. However, there is fragmentary evidence concerning the educational correlates of internal migration in sub-Saharan Africa. Objective: The study questions whether more precise measures of migration in Health and Demographic Surveillance System (HDSS populations support the hypothesis that migrants are self-selected on human capital and more educated people are more likely to leave rural areas or enter urban areas within a geographical region. Methods: Using unique longitudinal data representing approximately 900,000 people living in eight sub-Saharan African HDSS sites that are members of the INDEPTH Network, the paper uses Event History Analysis techniques to examine the relationship between formal educational attainment and in- and out-migration, over the period 2009 to 2011. Results: Between 7Š and 27Š of these local populations are moving in or out of the HDSS area over this period. Education is positively associated with both in- and out-migration in the Kenyan HDSS areas; however, the education effect has no clear pattern in the HDSS sites in Burkina Faso, Mozambique, and South Africa. Conclusions: Empirical results presented in this paper confirm a strong age profile of migration consistent with human capital expectation, yet the results point to variability in the association of education and the propensity to migrate. In particular, the hypothesis of a shift of human capital from rural to urban areas is not universally valid.

  1. Discordance in selected designee for return of genomic findings in the event of participant death and estate executor.

    Science.gov (United States)

    Goodman, Jessie L; Amendola, Laura M; Horike-Pyne, Martha; Trinidad, Susan B; Fullerton, Stephanie M; Burke, Wylie; Jarvik, Gail P

    2017-03-01

    Legal and ethical questions arise regarding disseminating genetic research results to family members in the event of a research participant's death; failure to return or return to legal next of kin or estate executor may not reflect participant desires. We sought to determine participant preferences for whether and to whom they would like their data released in the case of their death prior to receiving genomic results, focusing on whether the person selected was also their estate executor. The University of Washington NEXT Medicine Study of the Clinical Sequencing Exploratory Research program previously reported participant preferences regarding designating an individual to receive genomic results in the event of death, including whether they want results shared, and if so, with what person. Participants were also asked whether this designee is executor of their will or estate. To date, 61 individuals were asked about the concordance of their study designee and legal representative: 42 (69%) reported having a will or estate plan and of these, 14 (33%) chose someone other than their executor to receive their results. For the 14 who chose someone other than their estate executor to receive genetic results, 12 (86%) chose a family member, typically a biological relative, as their designee. Those with a different genomic designee than their executor were less likely to be partnered ( P  = 0.0024). For those partnered participants without an estate plan, spouses were not always chosen for return of genomic results. For one-third of our participants, the individual deemed most appropriate by the participant to receive their genomic results was not the executor. In the absence of an explicit designation, HIPAA may prohibit access to genomic results to persons other than the executor; hence asking for designation at the time of study enrollment (or initiation of clinical testing) is important.

  2. U.S. Migration and Reproductive Health among Mexican Women: Assessing the Evidence for Health Selectivity

    Directory of Open Access Journals (Sweden)

    Alexandra M. Minnis

    2010-10-01

    Full Text Available Health selectivity posits that individuals who practice preventive health behaviors are more likely to migrate to the United States, and this has been proposed as one explanation of the Latino Paradox. This paper examines evidence for health selection in the context of reproductive health using national survey data from Mexico (the longitudinal Mexico Family Life Survey [MxFLS], 2002 and 2005 waves and the United States (the National Survey of Family Growth [NSFG], 2002. We compared sexual behaviors and contraceptive practices of Mexican women residing in Mexico who subsequently migrated to the United States with those who remained in Mexico and with Mexican immigrants in the United States. MxFLS respondents who migrated to the United States had a younger mean age, and a larger proportion had no children compared to MxFLS nonmigrants. Within the MxFLS sample, a smaller proportion of women who migrated had ever had vaginal sex, though this difference was nonsignificant with adjustment for sociodemographic factors. No sexual behavior or contraceptive use measures varied between Mexican migrants and nonmigrants within the MxFLS. The mean lifetime number of sexual partners was lower for MxFLS respondents than for Mexican immigrants in the NSFG. Smaller proportions of MxFLS respondents reported using hormonal methods or condoms relative to NSFG respondents. We found no evidence for health selectivity with regard to sexual behaviors or contraceptive practices, underscoring the importance of continued attention to the factors that influence the adaptation trajectories following U.S. migration.L’hypothèse de la sélection par la santé selon laquelle les individus qui adoptent des comportements de prévention sont plus susceptibles d’immigrer aux Etats-Unis, a été proposée comme une explication au paradoxe latino. Cet article examine les signes de sélection par la santé dans le contexte de la santé en matière de procréation sur la base des

  3. Robust portfolio selection based on asymmetric measures of variability of stock returns

    Science.gov (United States)

    Chen, Wei; Tan, Shaohua

    2009-10-01

    This paper addresses a new uncertainty set--interval random uncertainty set for robust optimization. The form of interval random uncertainty set makes it suitable for capturing the downside and upside deviations of real-world data. These deviation measures capture distributional asymmetry and lead to better optimization results. We also apply our interval random chance-constrained programming to robust mean-variance portfolio selection under interval random uncertainty sets in the elements of mean vector and covariance matrix. Numerical experiments with real market data indicate that our approach results in better portfolio performance.

  4. Least-squares reverse time migration of marine data with frequency-selection encoding

    KAUST Repository

    Dai, Wei; Huang, Yunsong; Schuster, Gerard T.

    2013-01-01

    The phase-encoding technique can sometimes increase the efficiency of the least-squares reverse time migration (LSRTM) by more than one order of magnitude. However, traditional random encoding functions require all the encoded shots to share

  5. The intake of selected foods by six-year-old Swedish children differs according to parental education and migration status.

    Science.gov (United States)

    Säfsten, Eleonor; Nyberg, Gisela; Elinder, Liselotte Schäfer; Norman, Åsa; Patterson, Emma

    2016-04-01

    Little is known about how parental migration status may be associated with children's diets. We examined whether the intake of selected foods by six-year-old children differed according to their parents' migration status, taking education level into account. This study used pooled baseline data from two clustered randomised controlled trials of A Healthy School Start, conducted in municipalities of low-to-medium socio-economic status in Stockholm County, Sweden. The children's intake of selected healthy and unhealthy foods was reported by parents using the Eating and Physical Activity Questionnaire, and the children's height and weight were measured. Parental education and country of birth were self-reported. Data were available for 520 children. Low parental education was associated with significantly higher intakes of fruit, higher intakes of several unhealthy foods and lower intakes of vegetables. Children of parents born outside the Nordic region had higher intakes of all unhealthy foods as well as fruit and vegetables, even when adjusted for education. A negative association between high education and overweight was only seen in children of Nordic-born parents. Parental migration status was a strong predictor of the intake of selected foods and was a stronger predictor than parental education. ©2015 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  6. The Effects of Voluntary Return Programmes on Migration Flows in the Context of the 1973/74 and 2008/09 Economic Crises

    Directory of Open Access Journals (Sweden)

    Piotr Plewa

    2012-10-01

    Full Text Available The article analyses Spain’s voluntary return policies, including the programme instituted specifically to assist migrants affected by the 2008/09 crisis. Voluntary return policies were implemented in Europe in the context of the 1973/4 crisis. Just like the Western European programmes of the 1970s and the 1980s, the current Spanish voluntary return policies also only elicited the cooperation of small numbers of migrants and countries of origin. The article recommends four broader policy measures to tackle the emerging trend whereby a considerable proportion of migrants will stay in Spain rather than repatriate.

  7. Rationalization of the selectivity between 1,3- and 1,2-migration: a DFT study on gold(i)-catalyzed propargylic ester rearrangement.

    Science.gov (United States)

    Jiang, Jingxing; Liu, Yan; Hou, Cheng; Li, Yinwu; Luan, Zihong; Zhao, Cunyuan; Ke, Zhuofeng

    2016-04-14

    Gold catalyzed rearrangement of propargylic esters can undergo 1,3-acyloxy migration to form allenes, or undergo 1,2-acyloxy migration to access gold-carbenoids. The variation in migration leads to different reactivities and diverse cascade transformations. The effect of terminal substituents is very important for the rearrangement. However, it remains ambiguous how terminal substituents govern the selectivity of the rearrangement. This study presents a theoretical model based on the resonance structure of gold activated propargylic ester complexes to rationalize the rearrangement selectivity. Substrates with a major resonance contributor A prefer 5-exo-dig cyclization (1,2-migration), while those with a major resonance contributor B prefer 6-endo-dig cyclization (1,3-migration). This concise model would be helpful in understanding and tuning the selectivity of the metal catalyzed rearrangement of propargylic esters.

  8. Journalists and Their Role in Selecting and Building News on Contemporary Transnational Migrations

    Directory of Open Access Journals (Sweden)

    Elaine Javorski

    2017-08-01

    Full Text Available Over the last decade, Brazil has once more become a gateway for immigrants from different nations. This article presents a form for understanding the journalist’s role in selecting and building news on contemporary transnational migrations. In order to do this, a content analysis was made of excerpts from national and regional morning newscasts between 2014 and 2016 from Globo Network, Bom Dia Brasil and Bom Dia Paraná. The second stage of the investigation was a study of journalists from Paraná radio stations. This study consisted of a questionnaire and a focus group to help understand what kind of barriers journalists face when selecting news. The results show the limits for using personal experiences in news production and the social differences between journalists and sources; considered as an obstacle towards bringing minority issues and the dependence on bureaucratic sources to the forefront. O Brasil tornou-se, na última década, novamente a porta de entrada de imigrantes. É no sentido de compreender o papel do jornalista na seleção e construção da notícia sobre as migrações transnacionais contemporâneas que esse artigo se apresenta. Para tanto, foi realizada uma análise de conteúdo de peças encontradas nos telejornais matutinos de âmbito nacional e regional da TV Globo, Bom Dia Brasil e Bom Dia Paraná, entre 2014 e 2016. A segunda etapa da investigação consistiu em uma pesquisa com jornalistas de emissoras paranaenses por meio de questionários e da composição de um grupo focal na intenção de perceber, à luz da teoria do gatekeeping, quais as interferências sofridas pelos jornalistas na seleção das notícias. Os resultados apontam os limites da utilização das experiências pessoais na produção da notícia, as diferenças sociais entre jornalistas e fontes como empecilho para a visibilidade de assuntos referentes às minorias e a dependência das fontes burocráticas. El Brasil se ha convertido, en la

  9. Drift, selection, or migration? Processes affecting genetic differentiation and variation along a latitudinal gradient in an amphibian.

    Science.gov (United States)

    Cortázar-Chinarro, Maria; Lattenkamp, Ella Z; Meyer-Lucht, Yvonne; Luquet, Emilien; Laurila, Anssi; Höglund, Jacob

    2017-08-14

    Past events like fluctuations in population size and post-glacial colonization processes may influence the relative importance of genetic drift, migration and selection when determining the present day patterns of genetic variation. We disentangle how drift, selection and migration shape neutral and adaptive genetic variation in 12 moor frog populations along a 1700 km latitudinal gradient. We studied genetic differentiation and variation at a MHC exon II locus and a set of 18 microsatellites. Using outlier analyses, we identified the MHC II exon 2 (corresponding to the β-2 domain) locus and one microsatellite locus (RCO8640) to be subject to diversifying selection, while five microsatellite loci showed signals of stabilizing selection among populations. STRUCTURE and DAPC analyses on the neutral microsatellites assigned populations to a northern and a southern cluster, reflecting two different post-glacial colonization routes found in previous studies. Genetic variation overall was lower in the northern cluster. The signature of selection on MHC exon II was weaker in the northern cluster, possibly as a consequence of smaller and more fragmented populations. Our results show that historical demographic processes combined with selection and drift have led to a complex pattern of differentiation along the gradient where some loci are more divergent among populations than predicted from drift expectations due to diversifying selection, while other loci are more uniform among populations due to stabilizing selection. Importantly, both overall and MHC genetic variation are lower at northern latitudes. Due to lower evolutionary potential, the low genetic variation in northern populations may increase the risk of extinction when confronted with emerging pathogens and climate change.

  10. Riders on the storm: selective tidal movements facilitate the spawning migration of threatened delta smelt in the San Francisco Estuary

    Science.gov (United States)

    Bennett, W.A.; Burau, Jon R.

    2015-01-01

    Migration strategies in estuarine fishes typically include behavioral adaptations for reducing energetic costs and mortality during travel to optimize reproductive success. The influence of tidal currents and water turbidity on individual movement behavior were investigated during the spawning migration of the threatened delta smelt, Hypomesus transpacificus, in the northern San Francisco Estuary, California, USA. Water current velocities and turbidity levels were measured concurrently with delta smelt occurrence at sites in the lower Sacramento River and San Joaquin River as turbidity increased due to first-flush winter rainstorms in January and December 2010. The presence/absence of fish at the shoal-channel interface and near the shoreline was quantified hourly over complete tidal cycles. Delta smelt were caught consistently at the shoal-channel interface during flood tides and near the shoreline during ebb tides in the turbid Sacramento River, but were rare in the clearer San Joaquin River. The apparent selective tidal movements by delta smelt would facilitate either maintaining position or moving upriver on flood tides, and minimizing advection down-estuary on ebb tides. These movements also may reflect responses to lateral gradients in water turbidity created by temporal lags in tidal velocities between the near-shore and mid-channel habitats. This migration strategy can minimize the energy spent swimming against strong river and tidal currents, as well as predation risks by remaining in turbid water. Selection pressure on individuals to remain in turbid water may underlie population-level observations suggesting that turbidity is a key habitat feature and cue initiating the delta smelt spawning migration.

  11. Opportunistically collected data reveal habitat selection by migrating Whooping Cranes in the U.S. Northern Plains

    Science.gov (United States)

    Niemuth, Neil D.; Ryba, Adam J.; Pearse, Aaron T.; Kvas, Susan M.; Brandt, David; Wangler, Brian; Austin, Jane; Carlisle, Martha J.

    2018-01-01

    The Whooping Crane (Grus americana) is a federally endangered species in the United States and Canada that relies on wetland, grassland, and cropland habitat during its long migration between wintering grounds in coastal Texas, USA, and breeding sites in Alberta and Northwest Territories, Canada. We combined opportunistic Whooping Crane sightings with landscape data to identify correlates of Whooping Crane occurrence along the migration corridor in North Dakota and South Dakota, USA. Whooping Cranes selected landscapes characterized by diverse wetland communities and upland foraging opportunities. Model performance substantially improved when variables related to detection were included, emphasizing the importance of accounting for biases associated with detection and reporting of birds in opportunistic datasets. We created a predictive map showing relative probability of occurrence across the study region by applying our model to GIS data layers; validation using independent, unbiased locations from birds equipped with platform transmitting terminals indicated that our final model adequately predicted habitat use by migrant Whooping Cranes. The probability map demonstrated that existing conservation efforts have protected much top-tier Whooping Crane habitat, especially in the portions of North Dakota and South Dakota that lie east of the Missouri River. Our results can support species recovery by informing prioritization for acquisition and restoration of landscapes that provide safe roosting and foraging habitats. Our results can also guide the siting of structures such as wind towers and electrical transmission and distribution lines, which pose a strike and mortality risk to migrating Whooping Cranes.

  12. Some economic effects of recent migration patterns on central cities.

    Science.gov (United States)

    Sternlieb, G; Hughes, J W

    1981-01-01

    The authors examine demographic changes in central cities of the United States between 1970 and 1977 and the economic effects of these changes. Patterns of selective migration from central cities, particularly the general out-migration of the middle class and the recent return of the middle class to selected areas, are discussed. Changes in household and family patterns, racial composition, income, and poverty status are examined, and the aggregate impact of migration on resident incomes and purchasing power within central cities is analyzed. The findings show a continued concentration of poverty in central cities.

  13. Selective extractions in uranium migration studies - Findings from a natural analogue study at Palmottu

    International Nuclear Information System (INIS)

    Suksi, J.; Saarinen, L.

    1994-01-01

    The usefulness of chemical extractions in the study on uranium migration is considered in the light of the results compiled at Palmottu. Chemical extractions provide a method for evaluating the mass transfer of U and its retardation in geochemical cycling. The present detailed study provides more specific information on the in situ fixation of U on rock materials. The many observations made at Palmottu show the potential of the method to fill the gap in interpretations between the natural partitioning of U in rock and the distribution of artificial tracers determined by the short-term laboratory experiments. (orig.) (20 refs., 4 figs., 1 tab.)

  14. Return of qualified Sudanese

    OpenAIRE

    Lindsay T McMahon

    2007-01-01

    With the signing of the Comprehensive Peace Agreement in January 2005, the new Government of South Sudan began to call for the return of the millions of South Sudanese IDP s and refugees. The International Organization for Migration (IOM) has developed a programme to help them do so.

  15. Return of qualified Sudanese

    Directory of Open Access Journals (Sweden)

    Lindsay T McMahon

    2007-07-01

    Full Text Available With the signing of the Comprehensive Peace Agreement in January 2005, the new Government of South Sudan began to call for the return of the millions of South Sudanese IDP s and refugees. The International Organization for Migration (IOM has developed a programme to help them do so.

  16. In Situ Pre-Selection of Return Samples with Bio-Signatures by Combined Laser Mass Spectrometry and Optical Microscopy

    Science.gov (United States)

    Wiesendanger, R.; Wurz, P.; Tulej, M.; Wacey, D.; Neubeck, A.; Grimaudo, V.; Riedo, A.; Moreno, P.; Cedeño-López, A.; Ivarsson, M.

    2018-04-01

    The University of Bern developed instrument prototypes that allow analysis of samples on Mars prior to bringing them back to Earth, allowing to maximize the scientific outcome of the returned samples. We will present the systems and first results.

  17. Plans for Selection and In-Situ Investigation of Return Samples by the Supercam Instrument Onboard the Mars 2020 Rover

    Science.gov (United States)

    Wiens, R. C.; Maurice, S.; Mangold, N.; Anderson, R.; Beyssac, O.; Bonal, L.; Clegg, S.; Cousin, A.; DeFlores, L.; Dromart, G.; Fisher, W.; Forni, O.; Fouchet, T.; Gasnault, O.; Grotzinger, J.; Johnson, J.; Martinez-Frias, J.; McLennan, S.; Meslin, P.-Y.; Montmessin, F.; Poulet, F.; Rull, F.; Sharma, S.

    2018-04-01

    The SuperCam instrument onboard Rover 2020 still provides a complementary set of analyses with IR reflectance and Raman spectroscopy for mineralogy, LIBS for chemistry, and a color imager in order to investigate in-situ samples to return.

  18. The 'successful' return

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2012-01-01

    Research on female migrant caregivers has tended to focus upon the emotional and social problems they encounter working abroad, given women’s traditional role as caregivers for their own families. This article analyses how Caribbean women who have returned after a period abroad as domestic workers...... inscribe their migration experiences within the gendered narrative of the good relative who migrates to help the family left behind and therefore deserves social recognition in the community of origin. It argues that this narrative allows the women to both affirm and reinterpret local family and gender...... roles within the context of migration. This analysis points to the close connection between narrative structures, accounts of migration experiences, and self-presentations and suggests that narratives about family and gender roles not only reflect people’s lives, but are also a malleable resource...

  19. Jump-and-return sandwiches: A new family of binomial-like selective inversion sequences with improved performance

    Science.gov (United States)

    Brenner, Tom; Chen, Johnny; Stait-Gardner, Tim; Zheng, Gang; Matsukawa, Shingo; Price, William S.

    2018-03-01

    A new family of binomial-like inversion sequences, named jump-and-return sandwiches (JRS), has been developed by inserting a binomial-like sequence into a standard jump-and-return sequence, discovered through use of a stochastic Genetic Algorithm optimisation. Compared to currently used binomial-like inversion sequences (e.g., 3-9-19 and W5), the new sequences afford wider inversion bands and narrower non-inversion bands with an equal number of pulses. As an example, two jump-and-return sandwich 10-pulse sequences achieved 95% inversion at offsets corresponding to 9.4% and 10.3% of the non-inversion band spacing, compared to 14.7% for the binomial-like W5 inversion sequence, i.e., they afforded non-inversion bands about two thirds the width of the W5 non-inversion band.

  20. No Habitat Selection during Spring Migration at a Meso-Scale Range across Mosaic Landscapes: A Case Study with the Woodcock (Scolopax rusticola.

    Directory of Open Access Journals (Sweden)

    Ariñe Crespo

    Full Text Available Success of migration in birds in part depends on habitat selection. Overall, it is still poorly known whether there is habitat selection amongst landbird migrants moving across landscapes. Europe is chiefly covered by agro-forestry mosaic landscapes, so migratory species associated to either agricultural landscapes or woodland habitats should theoretically find suitable stopover sites along migration. During migration from wintering to breeding quarters, woodcocks (Scolopax rusticola tagged with PTT satellite-tracking transmitters were used to test for the hypothesis that migrants associated to agro-forest habitats have no habitat selection during migration, at a meso-scale level. Using a GIS platform we extracted at a meso-scale range habitat cover at stopover localities. Results obtained from comparisons of soil covers between points randomly selected and true stopover localities sites revealed, as expected, the species may not select for particular habitats at a meso-scale range, because the habitat (or habitats required by the species can be found virtually everywhere on their migration route. However, those birds stopping over in places richer in cropland or mosaic habitats including both cropland and forest and with proportionally less closed forest stayed for longer than in areas with lower surfaces of cropland and mosaic and more closed forest. This suggests that areas rich in cropland or mosaic habitat were optimal.

  1. Evolution of the composition of a selected bitter Camembert cheese during ripening: release and migration of taste-active compounds.

    Science.gov (United States)

    Engel, E; Tournier, C; Salles, C; Le Quéré, J L

    2001-06-01

    The aim of this study was to add to the understanding of changes in taste that occur during the ripening of a bitter Camembert cheese by the evolution of its composition. Physicochemical analyses were performed on rind, under-rind, and center portions of a Camembert cheese selected for its intense bitterness. At each of the six steps of ripening studied organic acids, sugars, total nitrogen, soluble nitrogen, phosphotungstic acid soluble nitrogen, non-protein nitrogen, Na, K, Ca, Mg, Pi, Cl, and biogenic amines were quantified in each portion. Changes in cheese composition seemed to mainly result from the development of Penicillium camemberti on the cheese outer layer. Migration phenomena and the release of potentially taste-active compounds allowed for the evolution of saltiness, sourness, and bitterness throughout ripening to be better understood. Apart from taste-active compounds, the impact of the cheese matrix on its taste development is discussed.

  2. Assessment of toxic and endocrine potential of substances migrating from selected toys and baby products.

    Science.gov (United States)

    Szczepańska, Natalia; Namieśnik, Jacek; Kudłak, Błażej

    2016-12-01

    Analysis of literature data shows that there is limited information about the harmful biological effects of mixture of compounds from the EDC group that are released from the surface of toys and objects intended for children and infants. One of the tools that can be used to obtain such information is appropriate bioanalytical tests. The aim of this research involved determining whether tests that use living organisms as an active element (Vibrio fischeri-Microtox®, Heterocypris incongruens-Ostrocodtoxkit F™ and the XenoScreen YES/YAS™ test of oestrogenic/androgenic activity) can be a tool for estimating the combined toxic effects induced by xenobiotics released from objects intended for children. To reproduce the conditions to which objects are exposed during their use, liquids with a composition corresponding to that of human bodily fluids (artificial sweat and saliva) were used. This research focused on the main parameters influencing the intensification of the migration process (temperature, contact time and composition of the extraction mixture). The studies aimed to estimate the endocrine potential of the extracts showed that compounds released from the surface of studied objects exhibit antagonistic androgenic activity. While on the basis of the results of Microtox® test, one can state that the largest quantity of toxic compounds are released in the first 2 h of using the object. The FTIR spectra analyses confirmed that no degradation of polymeric material took place. On the basis of the results obtained, it was unanimously concluded that contact of the object with bodily fluids may result in the release of a large number of xenobiotics, which has disadvantageous effects on the metabolic processes of the indicator organisms.

  3. Application of Generalized Student’s T-Distribution In Modeling The Distribution of Empirical Return Rates on Selected Stock Exchange Indexes

    Directory of Open Access Journals (Sweden)

    Purczyńskiz Jan

    2014-07-01

    Full Text Available This paper examines the application of the so called generalized Student’s t-distribution in modeling the distribution of empirical return rates on selected Warsaw stock exchange indexes. It deals with distribution parameters by means of the method of logarithmic moments, the maximum likelihood method and the method of moments. Generalized Student’s t-distribution ensures better fitting to empirical data than the classical Student’s t-distribution.

  4. Migration chemistry

    International Nuclear Information System (INIS)

    Carlsen, L.

    1992-05-01

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional K D concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  5. The economics of amenities and migration in the Pacific Northwest: review of selected literature with implications for national forest management.

    Science.gov (United States)

    Brian E. Garber-Yonts

    2004-01-01

    This paper reviews literature on the influence of nonmarket amenity resources on population migration. Literature reviewed includes migration and demographic studies; urban and regional economics studies of amenities in labor markets, retirement migration, and firm location decisions; nonmarket valuation studies using hedonic price analysis of amenity resource values;...

  6. Strategy for a consistent selection of radionuclide migration parameters for the Belgian safety and feasibility case-1

    International Nuclear Information System (INIS)

    Bruggeman, C.; Maes, N.; Salah, S.; Brassinnes, S.; Van Geet, M.

    2010-01-01

    Document available in extended abstract form only. The purpose of this presentation is to describe the strategy for the selection of retention and migration parameters for safety-relevant nuclides that was developed in the framework of the Belgian Safety and Feasibility Case SFC-1. A geochemical database containing state-of-the-art retention and migration parameters of all safety-relevant radionuclides, is ideally based on a thermodynamic understanding and an ability to accurately describe the geochemical and transport behaviour of all these radionuclides under the geochemical conditions that are considered for a reference host formation. In Belgium, this reference formation is Boom Clay. The parameters will be used in Performance Assessment (PA) calculations, and therefore must also be adapted to PA models. Since these models currently use only a four parameters for every radionuclide, the whole geochemical and transport behaviour must be comprised to a very limited parameter set that describe on the one hand chemical retention within the Boom Clay formation, and on the other hand transport through the Boom Clay formation. Chemical retention considers two concepts: 1) a concentration limit (S), which represents the mobile concentration of a nuclide present in the aqueous phase under undisturbed far field Boom Clay conditions; 2) a retardation (R/Kd) factor, which represents the uptake of a mobile nuclide by the inorganic and organic phases present in the Boom Clay formation. For mobility/migration two additional concepts are introduced: 3) the diffusion accessible porosity (η), which is the total physical space available for transport of a nuclide. The maximum value of η is limited by the water content of the formation; 4) the pore diffusion coefficient (Dp), which represents the transport velocity of a nuclide in a diffusion-dominated system. Within the framework of SFC-1, primary focus is laid on the compilation of parameter ranges, instead of individual &apos

  7. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  8. Ionization-induced solvent migration in acetanilide-methanol clusters inferred from isomer-selective infrared spectroscopy.

    Science.gov (United States)

    Weiler, Martin; Nakamura, Takashi; Sekiya, Hiroshi; Dopfer, Otto; Miyazaki, Mitsuhiko; Fujii, Masaaki

    2012-12-07

    We present the resonance-enhanced multiphoton ionization, infrared-ultraviolet hole burning (IR-UV HB), and IR dip spectra of the trans-acetanilide-methanol (AA-MeOH) cluster in the S(0), S(1), and cationic ground state (D(0)) in a supersonic jet. The IR-UV HB spectra demonstrate the co-existence of two isomers in S(0,1), in which MeOH binds either to the NH or the CO site of the peptide linkage in AA, denoted as AA(NH)-MeOH and AA(CO)-MeOH. When AA(CO)-MeOH is selectively ionized, its IR spectrum in D(0) is the same as that measured for AA(+) (NH)-MeOH. Thus, photoionization of AA(CO)-MeOH induces migration of MeOH from the CO to the NH site with 100% yield. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Migration and Rural Development: Selected Topics for Teaching and Research. FAO Economic and Social Development Paper 3.

    Science.gov (United States)

    Du Guerny, J.

    In their role as change agents, rural development personnel often modify the environment in which they are operating when they introduce different technology, institutional modifications, etc. Because these actions can change the relationship between the rural population and its habitat and may encourage out-migration or in-migration, rural…

  10. Distinctive and selective route of PI3K/PKCα-PKCδ/RhoA-Rac1 signaling in osteoclastic cell migration.

    Science.gov (United States)

    Kim, Jin-Man; Kim, Mi Yeong; Lee, Kyunghee; Jeong, Daewon

    2016-12-05

    Cell migration during specialized stages of osteoclast precursors, mononuclear preosteoclasts, and multinucleated mature osteoclasts remain uncertain. M-CSF- and osteopontin-induced osteoclastic cell migration was inhibited by function-blocking monoclonal antibodies specific to the integrin αv and β3 subunits, suggesting that integrin αvβ3 mediates migratory signaling induced by M-CSF and osteopontin. M-CSF and osteopontin stimulation was shown to regulate two branched signaling processes, PI3K/PKCα/RhoA axis and PI3K/PKCδ/Rac1 axis. Interestingly, inactivation of RhoA or Rac1 blocked preosteoclast and mature osteoclast migration but not osteoclast precursor migration in a transwell-based cell migration assay. Moreover, the inhibitory effect on preosteoclast and mature osteoclast migration induced by Rac1 inactivation was more effective than that by RhoA inactivation. Collectively, our findings suggest that osteoclast precursor migration depends on PI3K/PKCα-PKCδ signaling mediated via integrin αvβ3 bypassing RhoA and Rac1, whereas preosteoclast and mature osteoclast migration relies on PI3K/PKCα-PKCδ/RhoA-Rac1 axis signaling mediated via integrin αvβ3 with increased dependency on PKCδ/Rac1 signaling route as differentiation progresses. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. A density gradient of VAPG peptides on a cell-resisting surface achieves selective adhesion and directional migration of smooth muscle cells over fibroblasts.

    Science.gov (United States)

    Yu, Shan; Zuo, Xingang; Shen, Tao; Duan, Yiyuan; Mao, Zhengwei; Gao, Changyou

    2018-05-01

    Selective adhesion and migration of smooth muscle cells (SMCs) over fibroblasts (FIBs) is required to prevent adventitia fibrosis in vascular regeneration. In this study, a uniform cell-resisting layer of poly(ethylene glycol) (PEG) with a density gradient of azide groups was generated on a substrate by immobilizing two kinds of PEG molecules in a gradient manner. A density gradient of alkynyl-functionalized Val-Ala-Pro-Gly (VAPG) peptides was then prepared on the PEG layer via click chemistry. The VAPG density gradient was characterized by fluorescence imaging, revealing the gradual enhancement of the fluorescent intensity along the substrate direction. The adhesion and mobility of SMCs were selectively enhanced on the VAPG density gradient, leading to directional migration toward the higher peptide density (up to 84%). In contrast, the adhesion and mobility of FIBs were significantly weakened. The net displacement of SMCs also significantly increased compared with that on tissue culture polystyrene (TCPS) and that of FIBs on the gradient. The mitogen-activated protein kinase (MAPK) signaling pathways related to cell migration were studied, showing higher expressions of functional proteins from SMCs on the VAPG-modified surface in a density-dependent manner. For the first time the selective adhesion and directional migration of SMCs over FIBs was achieved by an elaborative design of a gradient surface, leading to a new insight in design of novel vascular regenerative materials. Selective cell adhesion and migration guided by regenerative biomaterials are extremely important for the regeneration of targeted tissues, which can avoid the drawbacks of incorrect and uncontrolled responses of tissue cells to implants. For example, selectivity of smooth muscle cells (SMCs) over fibroblasts (FIBs) is required to prevent adventitia fibrosis in vascular regeneration. Herein we prepare a uniform cell-repelling layer, on which SMCs-selective Val-Ala-Pro-Gly (VAPG) peptides

  12. The Return-risk Performance of Selected Pension Fund in OECD with Focus on the Czech Pension System

    OpenAIRE

    Petr Kupčík; Pavel Gottwald

    2016-01-01

    This paper focuses on the measuring and comparing investment performance of pension funds in selected European countries. Comparison of the investment performance of pension funds is determined by means of the Sharpe ratio and the Sortino ratio. We used data of nominal appreciation of pension funds from the Czech Republic, Slovakia, Poland, Sweden, Switzerland and the Netherlands in the period 2005−2013. These countries were selected because they have many common features but Sweden, Switzerl...

  13. Is the male marriage premium due to selection? The effect of shotgun weddings on the return to marriage

    OpenAIRE

    Ginther, Donna; Zavodny, Madeline

    1998-01-01

    In standard cross-sectional wage regressions, married men appear to earn 10 to 20 percent more than comparable never-married men. One proposed explanation for this male marriage premium is that men may be selected into marriage on the basis of characteristics valued by employers as well as by spouses or because they earn high wages. This paper examines the selection hypothesis using a "natural experiment" that may make marital status uncorrelated with earnings ability for some men. We compare...

  14. The canonical equation of adaptive dynamics for life histories: from fitness-returns to selection gradients and Pontryagin's maximum principle.

    Science.gov (United States)

    Metz, Johan A Jacob; Staňková, Kateřina; Johansson, Jacob

    2016-03-01

    This paper should be read as addendum to Dieckmann et al. (J Theor Biol 241:370-389, 2006) and Parvinen et al. (J Math Biol 67: 509-533, 2013). Our goal is, using little more than high-school calculus, to (1) exhibit the form of the canonical equation of adaptive dynamics for classical life history problems, where the examples in Dieckmann et al. (J Theor Biol 241:370-389, 2006) and Parvinen et al. (J Math Biol 67: 509-533, 2013) are chosen such that they avoid a number of the problems that one gets in this most relevant of applications, (2) derive the fitness gradient occurring in the CE from simple fitness return arguments, (3) show explicitly that setting said fitness gradient equal to zero results in the classical marginal value principle from evolutionary ecology, (4) show that the latter in turn is equivalent to Pontryagin's maximum principle, a well known equivalence that however in the literature is given either ex cathedra or is proven with more advanced tools, (5) connect the classical optimisation arguments of life history theory a little better to real biology (Mendelian populations with separate sexes subject to an environmental feedback loop), (6) make a minor improvement to the form of the CE for the examples in Dieckmann et al. and Parvinen et al.

  15. The Return-risk Performance of Selected Pension Fund in OECD with Focus on the Czech Pension System

    Directory of Open Access Journals (Sweden)

    Petr Kupčík

    2016-01-01

    Full Text Available This paper focuses on the measuring and comparing investment performance of pension funds in selected European countries. Comparison of the investment performance of pension funds is determined by means of the Sharpe ratio and the Sortino ratio. We used data of nominal appreciation of pension funds from the Czech Republic, Slovakia, Poland, Sweden, Switzerland and the Netherlands in the period 2005−2013. These countries were selected because they have many common features but Sweden, Switzerland and the Netherlands were added to the analysis because we wanted to show the differences between a developed and less developed fully funded system. The last part of this article presents the main causes of the differences in investment performance of pension funds. Conclusions of the paper are focused on a comparison of the results of the Sharpe ratio and the Sortino ratio of pension funds from selected countries and recommendations for the Czech pension system. The article proposes a mechanism for determining the order of the negative Sharpe ratio and the Sortino ratio.

  16. Managing risk and expected financial return from selective expansion of operating room capacity: mean-variance analysis of a hospital's portfolio of surgeons.

    Science.gov (United States)

    Dexter, Franklin; Ledolter, Johannes

    2003-07-01

    Surgeons using the same amount of operating room (OR) time differ in their achieved hospital contribution margins (revenue minus variable costs) by >1000%. Thus, to improve the financial return from perioperative facilities, OR strategic decisions should selectively focus additional OR capacity and capital purchasing on a few surgeons or subspecialties. These decisions use estimates of each surgeon's and/or subspecialty's contribution margin per OR hour. The estimates are subject to uncertainty (e.g., from outliers). We account for the uncertainties by using mean-variance portfolio analysis (i.e., quadratic programming). This method characterizes the problem of selectively expanding OR capacity based on the expected financial return and risk of different portfolios of surgeons. The assessment reveals whether the choices, of which surgeons have their OR capacity expanded, are sensitive to the uncertainties in the surgeons' contribution margins per OR hour. Thus, mean-variance analysis reduces the chance of making strategic decisions based on spurious information. We also assess the financial benefit of using mean-variance portfolio analysis when the planned expansion of OR capacity is well diversified over at least several surgeons or subspecialties. Our results show that, in such circumstances, there may be little benefit from further changing the portfolio to reduce its financial risk. Surgeon and subspecialty specific hospital financial data are uncertain, a fact that should be taken into account when making decisions about expanding operating room capacity. We show that mean-variance portfolio analysis can incorporate this uncertainty, thereby guiding operating room management decision-making and reducing the chance of a strategic decision being made based on spurious information.

  17. Learning from HIV: exploring migration and health in South Africa.

    Science.gov (United States)

    Vearey, Joanna

    2012-01-01

    Southern Africa is associated with high HIV prevalence and diverse population movements, including temporary, circular movements between rural and urban areas within countries (internal migration), and movements across borders (international migration). Whilst most migration in southern Africa is associated with the search for improved livelihood opportunities in urban areas a small--but significant--number of people are forced to migrate to escape persecution or civil war. This paper utilises recent empirical studies conducted in South Africa to explore linkages between migration into urban areas and health, focusing on HIV. It is shown that the relationship between migration and HIV is complex; that both internal and international migrants move to urban areas for reasons other than healthcare seeking; and that most migratory movements into urban areas involve the positive selection of healthy individuals. Whilst healthy migration has economic benefits for rural sending households, the data uncovers an important process of return migration (internally or across borders) in times of sickness, with the burden of care placed on the rural, sending household. There is an urgent need for a comprehensive response that maintains the health of migrants in urban areas, and provides support to rural areas in times of sickness.

  18. Entry into working life : Internal migration and the job match quality of higher-educated graduates

    NARCIS (Netherlands)

    Venhorst, Viktor; Cörvers, Frank

    We estimate the impact of internal migration on job-match quality for recent Dutch university and college graduates. We find positive yet modest wage returns. After controlling for the self-selection of migrants with an IV approach, this effect is no longer significant for university graduates and

  19. Entry into working life: internal migration and the job match quality of higher-educated graduates

    NARCIS (Netherlands)

    Venhorst, V.; Cörvers, Frank

    2018-01-01

    We estimate the impact of internal migration on job-match quality for recent Dutch university and college graduates. We find positive yet modest wage returns. After controlling for the self-selection of migrants with an IV approach, this effect is no longer significant for university graduates and

  20. [On the selectivity of the migration process in Latin America, illustrated by the example of the southern Chilean lake region].

    Science.gov (United States)

    Bahr, J

    1979-01-01

    "Migration is studied at Puerto Montt and Osorno [Chile] where the immigrants' origins are examined. The life cycle and the education of the migrants, and their economic activity and trades are examined. In all variables the immigrants differed from the locals: but the migrants vary much between themselves. They can be of different ages, and come from different areas." excerpt

  1. Family migration and employment: the importance of migration history and gender.

    Science.gov (United States)

    Bailey, A J; Cooke, T J

    1998-01-01

    "This article uses event history data to specify a model of employment returns to initial migration, onward migration, and return migration among newly married persons in the U.S. Husbands are more likely to be full-time employed than wives, and being a parent reduces the employment odds among married women. Employment returns to repeated migration differ by gender, with more husbands full-time employed after onward migration and more wives full-time employed after return migration events. We interpret these empirical findings in the context of family migration theory, segmented labor market theory, and gender-based responsibilities." Data are from the National Longitudinal Survey of Youth from 1979 to 1991. excerpt

  2. Data analysis at the CMS level-1 trigger: migrating complex selection algorithms from offline analysis and high-level trigger to the trigger electronics

    CERN Document Server

    Wulz, Claudia

    2017-01-01

    With ever increasing luminosity at the LHC, optimum online data selection is becoming more and more important. While in the case of some experiments (LHCb and ALICE) this task is being completely transferred to computer farms, the others -- ATLAS and CMS -- will not be able to do this in the medium-term future for technological, detector-related reasons. Therefore, these experiments pursue the complementary approach of migrating more and more of the offline and high-level trigger intelligence into the trigger electronics. The presentation illustrates how the level-1 trigger of the CMS experiment and in particular its concluding stage, the so-called ``Global Trigger", take up this challenge.

  3. Gold Returns

    OpenAIRE

    Robert J. Barro; Sanjay P. Misra

    2013-01-01

    From 1836 to 2011, the average real rate of price change for gold in the United States is 1.1% per year and the standard deviation is 13.1%, implying a one-standard-deviation confidence band for the mean of (0.1%, 2.1%). The covariances of gold's real rate of price change with consumption and GDP growth rates are small and statistically insignificantly different from zero. These negligible covariances suggest that gold's expected real rate of return--which includes an unobserved dividend yiel...

  4. Migration of plasticizers from poly(vinyl chloride) and multilayer infusion bags using selective extraction and GC-MS.

    Science.gov (United States)

    Haned, Zohra; Moulay, Saad; Lacorte, Silvia

    2018-04-12

    Flexible poly(vinyl chloride) (PVC) is widely used in the pharmaceutical industry for the manufacture of medical devices (tubes, probes, bags, primary packaging, etc.). The objective of the present study was to develop a procedure to evaluate the migration potential of nine plastic additives in aqueous infusion bags (NaCl 0.9% and glucose 5%): five phthalates, one adipate, two alkylphenols, and benzophenone. Two types of materials were analyzed: (i) new and outdated plasticized PVC (containing 40% of diethylhexyl phthalate DEHP); and (ii) tri-laminate polyethylene-polyamide-polypropylene, a multilayer material presumably exempt from DEHP. In addition, we evaluated the migration of plasticizers from PVC raw materials (film and grain) under controlled conditions to compare the migration levels according to Regulation 2011/10. Solid phase extraction and liquid-liquid extraction with gas-chromatography coupled to mass spectrometry were used in all tests. The migration of DEHP in PVC grain exceeded the maximum regulated level of 5000 μg/kg, whereas the levels were much lower in films. In new PVC bags, DEHP was the only compound detected at 4.31 ± 0.5 μg/L in NaCl 0.9% and 4.29 ± 0.25 μg/L in glucose 5% serums, whereas the levels increased 10 times in three-year shelf-life bags. In multilayer bags, DEHP was not found but instead, two plasticizers were detected namely dibuthylphthalate (DBP) and diethylphthalate (DEP) at 0.7 ± 0.1 μg/L and 4.14 ± 0.6 μg/L, respectively. These plasticizers are not mentioned as additives allowed in materials intended for parenteral use (European Pharmacopoeia 8.0, 3.1.5. and 3.1.6.). Caprolactam was tentatively identified and could have stemmed from the polyamide of the multilayer composite. The levels of phthalates remained low but not negligible and might constitute a risk to public health in the case of reiterative infusions. Copyright © 2018. Published by Elsevier B.V.

  5. Reintegration upon return: insights from Ecuadorian returnees from Spain

    OpenAIRE

    Mercier, Marion; David, Anda; Mahia, Ramón; De Arce, Rafael

    2016-01-01

    Using the ECM2 survey data on Ecuadorian migrants returning from Spain, we investigate the determinants of reintegration upon return. We study how the migration experience, but also the before- and after-migration characteristics, correlate with migrants’ outcomes upon return. We adopt a broad conception of reintegration, considering jointly labour market-related outcomes that proxy for structural reintegration and subjective indicators that provide insights on sociocultural reintegration. Th...

  6. Repeat migration and disappointment.

    Science.gov (United States)

    Grant, E K; Vanderkamp, J

    1986-01-01

    This article investigates the determinants of repeat migration among the 44 regions of Canada, using information from a large micro-database which spans the period 1968 to 1971. The explanation of repeat migration probabilities is a difficult task, and this attempt is only partly successful. May of the explanatory variables are not significant, and the overall explanatory power of the equations is not high. In the area of personal characteristics, the variables related to age, sex, and marital status are generally significant and with expected signs. The distance variable has a strongly positive effect on onward move probabilities. Variables related to prior migration experience have an important impact that differs between return and onward probabilities. In particular, the occurrence of prior moves has a striking effect on the probability of onward migration. The variable representing disappointment, or relative success of the initial move, plays a significant role in explaining repeat migration probabilities. The disappointment variable represents the ratio of actural versus expected wage income in the year after the initial move, and its effect on both repeat migration probabilities is always negative and almost always highly significant. The repeat probabilities diminish after a year's stay in the destination region, but disappointment in the most recent year still has a bearing on the delayed repeat probabilities. While the quantitative impact of the disappointment variable is not large, it is difficult to draw comparisons since similar estimates are not available elsewhere.

  7. Internal migration and household living conditions in Ethiopia

    Directory of Open Access Journals (Sweden)

    Blessing Uchenna Mberu

    2006-06-01

    Full Text Available Using the 1998 Migration, Gender and Health Survey in Five Regions of Ethiopia, and multivariate regression techniques, this paper examines the relationship between internal migration and household living conditions. The analysis finds significant living condition advantage of permanent and temporary migrants over non-migrants. These advantages are primarily linked to migration selectivity by education and non-agricultural income. Once the independent effects of these variables are controlled, no statistical significant independent association exists between migration status and living conditions. Government policies of resettlement in the 1980s and ethnic federalism of the 1990s may have engendered stress migration and exacerbated poor living outcomes for return migrants. The resort to migration and/or resettlement as an individual or government policy response to periodic unfavorable conditions in places of origin is not strongly supported by this analysis as the key to improved living conditions. Promoting higher education and opportunities for employment outside the agricultural sector are more likely to yield improved living conditions in Ethiopia.

  8. Site selection and resource depletion in black-tailed godwits Limosa l. limosa eating rice during northward migration

    NARCIS (Netherlands)

    Lourenco, Pedro M.; Mandema, Freek S.; Hooijmeijer, Jos C.E.W.; Granadeiro, Jose P.; Piersma, Theunis; Bearhop, Stuart

    P>1. During migratory stopovers, animals are under strong time stress and need to maximize intake rates. We examine how foragers react to resource depletion by studying the foraging ecology and foraging site selection of black-tailed godwits Limosa l. limosa staging in rice fields during their

  9. Malaria burden in irregular migrants returning to Sri Lanka from human smuggling operations in West Africa and implications for a country reaching malaria elimination.

    Science.gov (United States)

    Wickramage, K; Galappaththy, G N L

    2013-05-01

    The number of malaria cases among irregular migrants returning to Sri Lanka has not been investigated. In the first 6 months of 2012 we screened 287 irregular migrants returning from seven West African nations to Sri Lanka for malaria to ascertain the risk of infection during migration. Four men were diagnosed as having malaria: three with Plasmodium falciparum had travelled to Togo and one with P. vivax had travelled to Guinea. The risk of contracting malaria was 14 cases per 1000. Facilitating a safe return with selective screening for at-risk inbound migrants flows is desirable as Sri Lanka advances towards its goal of malaria elimination.

  10. The Adaptive Change of HLA-DRB1 Allele Frequencies Caused by Natural Selection in a Mongolian Population That Migrated to the South of China.

    Directory of Open Access Journals (Sweden)

    Hao Sun

    Full Text Available Pathogen-driven balancing selection determines the richness of human leukocyte antigen (HLA alleles. Changes in the pathogen spectrum may cause corresponding changes in HLA loci. Approximately 700 years ago, a Mongolian population moved from the north of China to the Yunnan region in the south of China. The pathogen spectrum in the south of China differs from that in the north. In this study, changes in the HLA genes in the Yunnan Mongolian population, as well as the underlying mechanism, were investigated. A sequence-based typing method (SBT was used to genotype HLA-DRB1 in 470 individuals from two Mongolian populations and another five ethnic groups. Meanwhile, 10 autosomal short tandem repeats (STRs were genotyped to assess the influence of genetic background on HLA-DRB1 frequencies. The frequencies of certain alleles changed significantly in the Mongolian population that migrated to Yunnan. For example, DRB1*12:02:01 increased from 6.1% to 35.4%. STR analysis excluded the possibility of a recent bottleneck and indicated that 50% of the genetic consistency between northern and southern Mongolians; Tajima's D value for HLA-DRB1 exon2 and dN/dS analysis showed that the HLA-DRB1 genes in both Mongolian populations were under balancing selection. However, the sites under natural selection changed. We proposed that the dramatically change of HLA frequencies in southern Mongolian was caused by a combination of inter-population gene flow and natural selection. Certain diseases specific to the south of China, such as malaria, may be the driving force behind the enhanced DRB1*12:02:01 frequency.

  11. Novel optimum contribution selection methods accounting for conflicting objectives in breeding programs for livestock breeds with historical migration.

    Science.gov (United States)

    Wang, Yu; Bennewitz, Jörn; Wellmann, Robin

    2017-05-12

    Optimum contribution selection (OCS) is effective for increasing genetic gain, controlling the rate of inbreeding and enables maintenance of genetic diversity. However, this diversity may be caused by high migrant contributions (MC) in the population due to introgression of genetic material from other breeds, which can threaten the conservation of small local populations. Therefore, breeding objectives should not only focus on increasing genetic gains but also on maintaining genetic originality and diversity of native alleles. This study aimed at investigating whether OCS was improved by including MC and modified kinships that account for breed origin of alleles. Three objective functions were considered for minimizing kinship, minimizing MC and maximizing genetic gain in the offspring generation, and we investigated their effects on German Angler and Vorderwald cattle. In most scenarios, the results were similar for Angler and Vorderwald cattle. A significant positive correlation between MC and estimated breeding values of the selection candidates was observed for both breeds, thus traditional OCS would increase MC. Optimization was performed under the condition that the rate of inbreeding did not exceed 1% and at least 30% of the maximum progress was achieved for all other criteria. Although traditional OCS provided the highest breeding values under restriction of classical kinship, the magnitude of MC in the progeny generation was not controlled. When MC were constrained or minimized, the kinship at native alleles increased compared to the reference scenario. Thus, in addition to constraining MC, constraining kinship at native alleles is required to ensure that native genetic diversity is maintained. When kinship at native alleles was constrained, the classical kinship was automatically lowered in most cases and more sires were selected. However, the average breeding value in the next generation was also lower than that obtained with traditional OCS. For local

  12. The Psychology of Puerto Rican Migration.

    Science.gov (United States)

    Prewitt Diaz, Joseph O.

    The psychology of the Puerto Rican migrant to the United States mainland is explored. Puerto Ricans have been migrating to the U.S. mainland and returning to Puerto Rico for more than 125 years, and, in fact, approximately 57% of all Puerto Ricans have migrated at one time or another. The migrant experience, including the circular migration…

  13. Evaluation of resistance in a selected field strain of Haemonchus contortus to ivermectin and moxidectin using the Larval Migration on Agar Test

    Directory of Open Access Journals (Sweden)

    Fernanda S. Fortes

    2013-02-01

    Full Text Available Haemonchus contortus is one of the most common and economically significant causes of disease in small ruminants worldwide, and the control programs of parasitic nematodes - including H. contortus - rely mostly on the use of anthelmintic drugs. The consequence of the use of this, as the sole sanitary strategy to avoid parasite infections, was the reduction of the efficacy of all chemotherapeutic products with a heavy selection for resistance. The widespread of anthelmintic resistance and the difficulty of its early diagnosis has been a major concern for the sustainable parasite management on farms. The objective of this research was to determine and compare the ivermectin (IVM and moxidectin (MOX effect in a selected field strain of H. contortus with a known resistance status, using the in vitro larval migration on agar test (LMAT. Third stage larvae of the selected isolate were obtained from faecal cultures of experimentally infected sheep and incubated in eleven increasing diluted concentrations of IVM and MOX (6, 12, 24, 48, 96, 192, 384, 768, 1536, 3072 and 6144µg/mL. The dose-response sigmoidal curves were obtained using the R² value of >0.90 and the lethal concentration (LC50 dose for the tested anthelmintic drugs using a four-parameter logistic model. The LC50 value for MOX was significantly lower than IVM (1.253µg/mL and 91.06µg/mL, identifying the H. contortus isolate as considerably less susceptible to IVM compared to MOX. Furthermore, the LMAT showed a high consistency (p<0.0001 and provided to be a useful diagnostic tool for monitoring the resistance status of IVM and MOX in H. contortus field isolate, as well as it may be used for official routine drug monitoring programs under the Ministry of Agriculture (MAPA guidance.

  14. MIGRATION AND ITS ENVIROMENTAL EFFECTS

    OpenAIRE

    Rashid SAEED; Rana NADIR IDREES; Humna IJAZ; Marriam FURQANI; Raziya NADEEM

    2012-01-01

    Migration can be ongoing shifting of a particular person from one location to another. The reason of shifting depends on selected thought deficiency, shock, difficulties, hopes, enthusiasm. Case study ended up recognizing the extent to which in turn migration can be relying on the specifics especially natural environment. This particular document expects to research the actual linkages between the atmosphere as well as migration using secondary data. Lots of investigation may be completed wit...

  15. International Migration of Couples

    DEFF Research Database (Denmark)

    Junge, Martin; Munk, Martin D.; Nikolka, Till

    2018-01-01

    Migrant self-selection is important to labor markets and public finances in both origin and destination countries. We develop a theoretical model regarding the migration of dual-earner couples and test it using population-wide administrative data from Denmark. Our model predicts that the probabil...

  16. Economic Reintegration of Ethiopian Women Returned from the Middle East

    NARCIS (Netherlands)

    Nisrane, Beza L.; Morissens, Ann; Need, Ariana; Torenvlied, René

    2017-01-01

    Current migration studies and policy reviews neglect the vital link between migration experiences of labour migrants and their return and reintegration process. The objective of this study is to highlight the phenomenon and bring the matter to policy makers' attention. This study uses in-depth

  17. Socio-economic problems of returning migrants' reintegration in Georgia

    OpenAIRE

    TUKHASHVILI, Mirian

    2013-01-01

    CARIM-East: Creating an Observatory of Migration East of Europe Version in other language: Migration Policy Centre CARIM-East Research Report 2013/11 The present work of research reveals that despite an economic revival, the labour market infrastructure in Georgia and the cost of labour force do not contribute to any reduction in labour emigration. Therefore, great emphasis is placed on the facilitation of return migration back to the homeland and the socio-economic efficiency of ...

  18. Motorized Migrations: the Future or Mere Fantasy?

    Science.gov (United States)

    Ellis, D.H.; Sladen, William J. L.; Lishman, W.A.; Clegg, K.R.; Duff, J.W.; Gee, G.F.; Lewis, J.C.

    2003-01-01

    In 15 experiments from 1993-2002, we led cranes, geese, or swans on their first southward migration with either ultralight aircraft or vehicles on the ground. These experiments reveal that large birds can be readily trained to follow and most will return north (and south) in subsequent migrations unassisted. These techniques can now be used to teach birds new (or forgotten) migration paths. Although we are constantly improving our training techniques, we now have an operational program that can be broadly applied to those species where juveniles learn migration routes from their parents.

  19. Return of the Wetback

    Science.gov (United States)

    Portes, Alejandro

    1974-01-01

    Examines the wetback migration, and legal migration from Mexico which have had a vigorous resurgence in the years following the termination of the bracero program in 1964: the migrants, their methods and the making of the structural forces promoting and sustaining this migration do not conform to commonly held beliefs. (Author/JM)

  20. [International migration in the Middle East].

    Science.gov (United States)

    Beauge, G

    1985-01-01

    This special issue contains a selection of 12 papers by various authors on aspects of international migration to the Middle East. Papers are included on the impact of migration on socioeconomic development, income distribution, and rural capitalization in Egypt; migration from rural Lebanon; the effect of emigration on Pakistan; Indian workers in Oman; inter-Arab migration and development; the role of the state in migration in the Arab peninsula; the dynamics of manpower in Kuwait; the Iraqi model and Arab unity; and the impact of this migration on the concept of the New Economic Order.

  1. Migrating Worker

    DEFF Research Database (Denmark)

    Hansen, Hans

    This is the preliminary report on the results obtained in the Migrating Worker-project. This project was initiated by the Danish Ministry of Finance with the aim of illustrating the effects of the 1408/71 agreement and the bilateral double taxation agreements Denmark has with the countries included...

  2. Dateline Migration.

    Science.gov (United States)

    Tomasi, Lydio E., Ed.

    1995-01-01

    Presents data on international migration and its effects in and between various countries in North America, Europe, and Africa. Discussions include refugee, immigrant, and migrant worker flows; the legal, political, and social problems surrounding immigrants; alien terrorism and law enforcement problems; and migrant effects on education, social…

  3. Teaching migration routes to canada geese and trumpeter swans using ultralight aircraft, 1990-2001

    Science.gov (United States)

    Sladen, William J. L.; Lishman, W.A.; Ellis, D.H.; Shire, G.G.; Rininger, D.L.; Rees, Eileen C.; Earnst, Susan L.; Coulson, John C.

    2002-01-01

    This paper summarizes eleven years (1990-2001) of experiments to teach Canada Geese (Branta canadensis) and Trumpeter Swans (Cygnus buccinator) pre-selected migration routes using ultralight aircraft. When Canada Geese were trained to follow an ultralight aircraft for southward autumn migrations of 680 or 1,320 km, 81% (83/103) returned on their own in the next spring to near their place of training. In contrast, none returned of 21 similarly raised geese that were transported south in a closed truck over a route of 680 km. Trumpeter Swans have proven more difficult to train. However, in two experiments in which Trumpeter Swans followed an ultralight for the entire pre-selected route, one of three and two of four returned close to their training area. A stage-by-stage method, in which swans were transported in trucks between stops, flown in the vicinity and penned with a view of the night sky, has shown some promise. So far an established migration route (north and south twice) has been confirmed in only two geese

  4. Predictability of Stock Returns

    Directory of Open Access Journals (Sweden)

    Ahmet Sekreter

    2017-06-01

    Full Text Available Predictability of stock returns has been shown by empirical studies over time. This article collects the most important theories on forecasting stock returns and investigates the factors that affecting behavior of the stocks’ prices and the market as a whole. Estimation of the factors and the way of estimation are the key issues of predictability of stock returns.

  5. The Returns to Quality in Graduate Education

    Science.gov (United States)

    Stevenson, Adam

    2016-01-01

    This paper estimates the monetary return to quality in US graduate education, controlling for cognitive ability and self-selection across award level, program quality, and field-of-study. In most program types, I cannot reject the hypothesis of no returns to either degree completion or program quality. Important exceptions include master's…

  6. Variations in Withdrawal, Return Flow, and Consumptive Use of Water in Ohio and Indiana, with Selected Data from Wisconsin, 1999-2004

    Science.gov (United States)

    Shaffer, Kimberly H.

    2009-01-01

    This report contains an analysis of water withdrawal and return-flow data for Ohio and withdrawal data for Indiana and Wisconsin to compute consumptive-use coefficients and to describe monthly variability of withdrawals and consumptive use. Concurrent data were available for most water-use categories from 1999 through 2004. Average monthly water withdrawals are discussed for a variety of water-use categories, and average water use per month is depicted graphically for Ohio, Indiana, and Wisconsin (public supply only). For most water-use categories, the summer months were those of highest withdrawal and highest consumptive use. For public supply, average monthly withdrawals ranged from 1,380 million gallons per day (Mgal/d) (November) to 1,620 Mgal/d (July) in Ohio, 621 Mgal/d (December) to 816 Mgal/d (July) in Indiana, and 515 Mgal/d (December) to 694 Mgal/d (July) in Wisconsin. Ohio and Indiana thermoelectric facilities had large increases in average monthly withdrawals in the summer months (5,520 Mgal/d in March to 7,510 Mgal/d in August for Indiana; 7,380 Mgal/d in February to 10,040 Mgal/d in July for Ohio), possibly because of increased electricity production in the summer, a need for additional cooling-water withdrawals when intake-water temperature is high, or use of different types of cooling methods during different times of the year. Average industrial withdrawals ranged from 2,220 Mgal/d (December) to 2,620 Mgal/d (August) in Indiana and from 707 Mgal/d (January) to 787 Mgal/d (August) in Ohio. The Ohio and Indiana irrigation data showed that most withdrawals were in May through October for golf courses, nurseries, and crop irrigation. Commercial water withdrawals ranged from 30.4 Mgal/d (January) to 65.0 Mgal/d (September) in Indiana and from 23.2 Mgal/d (November) to 49.5 Mgal/d (August) in Ohio; commercial facilities that have high water demand in Ohio and Indiana are medical facilities, schools, amusement facilities, wildlife facilities, large stores

  7. Occupational change, employer change, internal migration, and earnings.

    Science.gov (United States)

    Krieg, R G

    1997-02-01

    "In this paper I use microdata from the [U.S.] Panel Study of Income Dynamics to measure the financial returns to intercounty and interstate migration for individuals in a temporal framework accounting for gains that accrue over time.... To account for the indirect effects of migration on earnings, explanatory variables are created by interacting migration status with: (1) occupational change, (2) employer change and (3) changes in both occupation and employer. These interaction terms are then included in the earnings functions. Earnings are estimated for three years subsequent to the migration decision to account for the financial returns to migration accruing over time. Results indicate that, when estimating earnings, the use of a simple migration dummy variable will mask the indirect effects of migration on earnings." excerpt

  8. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  9. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    philopatric movement of geese using a classic multi–state design. Previous studies of philopaty often rely upon simple return rates —however, good mark–recapture studies do not need to assume equal detection probabilities in space and time. This is likely the most important contribution of multi–state modelling to the study of movement. As with many of these studies, the most pressing problem in the analysis is the explosion in the number of parameters and the need to choose parsimonious modelss to get good precision. Drake and Alisauska demonstrate that model choice still remains an art with a great deal of biological insight being very helpful in the task. There is still plenty of scope for novel methods to study migration. Traditionally, there has been a clear cut distinction between birds being labelled as “migrant” or “resident” on the basis of field observations and qualitative interpretations of patterns of ring–recoveries. However, there are intermediate species where only part of the population migrates (partial migrants or where different components of the population migrate to different extents (differential migrants. Siriwardena, Wernham and Baillie (Siriwardena et al., 2004 develop a novel method that produces a quantitative index of migratory tendency. The method uses distributions of ringing–to–recovery distances to classify individual species’ patterns of movement relative to those of other species. The areas between species’ cumulative distance distributions are used with multi–dimensional scaling to produce a similarity map among species. This map can be used to investigate the factors that affect the migratory strategies that species adopt, such as body size, territoriality and distribution, and in studies of their consequences for demographic parameters such as annual survival and the timing of breeding. The key assumption of the method is the similar recovery effort of species over space and time. It would be interesting to

  10. [Prediction of cardiac function deviations (ECG data) in the course of permanent cosmonaut's monitoring starting from selection till return to earth after short-duration space flight].

    Science.gov (United States)

    Kotovskaia, A R; Koloteva, M I; Luk'ianiuk, V Iu; Stepanova, G P; Filatova, L M; Buĭlov, S P; Zhernavkov, A F; Kondratiuk, L L

    2007-01-01

    Analyzed were deviations in cardiac function in 29 cosmonauts with previous aviation and other occupations ranging of 29 to 61 y.o. who made 8- to 30-day space flights (totai number of flights = 34) between 1982 and 2006. The deviations were identified in ECG records collected during clinical selection, clinical physiological examination (CPE) before flight, insertion and deorbit in transport vehicles, and post-flight CPE. Based on the analysis, the cosmonauts were distributed into three groups. The first group (55.2% of the cosmonauts) did not exhibit noticeable shifts and unfavorable trends in ECG at any time of the period of observation. The second group (34.5%) showed some deviations during selection and pre-flight CPE that became more apparent in the period of deorbit and were still present in post-flight ECG records. The third group (10.3%) displayed health-threatening deviations in cardiac function during deorbit. These findings give start to important investigations with the purpose to define permissible medical risks and ensuing establishment and perfection of medical criteria for candidates to cosmonauts with certain health problems.

  11. Prostaglandin D2 inhibits airway dendritic cell migration and function in steady state conditions by selective activation of the D prostanoid receptor 1

    NARCIS (Netherlands)

    H. Hammad (Hamida); H.J. de Heer; T. Soullié (Thomas); H.C. Hoogsteden (Henk); F. Trottein; B.N.M. Lambrecht (Bart)

    2003-01-01

    textabstractPGD(2) is the major mediator released by mast cells during allergic responses, and it acts through two different receptors, the D prostanoid receptor 1 (DP1) and DP2, also known as CRTH2. Recently, it has been shown that PGD(2) inhibits the migration of epidermal

  12. Migration: the trends converge.

    Science.gov (United States)

    1985-09-01

    Formerly, Australia, New Zealand, Canada, and the US have served as permanent destinations for immigrants, while Europe's migrants have moved to more northerly countries to work for a time and then returned home. From 1973-1975 Europe's recruitment of foreign workers virtually ended, although family reunion for those immigrants allowed in was encouraged. Problems resulting from this new settlement migration include low paying jobs for immigrant women, high unemployment, and inadequate education for immigrant children. Illegal migrants from Latin America and the Caribbean enter the US and Canada each year while illegal North African immigrants enter Italy, Spain, and Greece. North America, Australia, and Europe have all received political refugees from Asia and Latin America. Increasingly, these foreigners compete in the labor market rather than simply fill jobs the native workers do not want. All the receiving countries have similar policy priorities: 1) more effective ways for controlling and monitoring inflows and checking illegal immigration; 2) encouraging normal living patterns and accepting refugees; and 3) integrating permanent migrants into the host country. Europe's public immigration encouragement prior to the first oil shock, has left some countries with a labor force that is reluctant to return home. It is unlikely that Europe will welcome foreign labor again in this decade, since unemployment among young people and women is high and family reunion programs may still bring in many immigrants. Less immigration pattern change will probably occur in North America, Australia, and New Zealand since these countries' populations are still growing and wages are more flexible. Immigration, regulated by policy, and emigration, determined by market forces, now are working in the same direction and will likely reduce future migration flows.

  13. Predictable return distributions

    DEFF Research Database (Denmark)

    Pedersen, Thomas Quistgaard

    trace out the entire distribution. A univariate quantile regression model is used to examine stock and bond return distributions individually, while a multivariate model is used to capture their joint distribution. An empirical analysis on US data shows that certain parts of the return distributions......-of-sample analyses show that the relative accuracy of the state variables in predicting future returns varies across the distribution. A portfolio study shows that an investor with power utility can obtain economic gains by applying the empirical return distribution in portfolio decisions instead of imposing...

  14. National and international graduate migration flows.

    Science.gov (United States)

    Mosca, Irene; Wright, Robert E

    2010-01-01

    This article examines the nature of national and international graduate migration flows in the UK. Migration equations are estimated with microdata from a matched dataset of Students and Destinations of Leavers from Higher Education, information collected by the Higher Education Statistical Agency. The probability of migrating is related to a set of observable characteristics using multinomial logit regression. The analysis suggests that migration is a selective process with graduates with certain characteristics having considerably higher probabilities of migrating, both to other regions of the UK and abroad.

  15. Family migration and relative earnings potentials

    DEFF Research Database (Denmark)

    Foged, Mette

    2016-01-01

    of husband centered migration. Couples are more likely to migrate if household earnings potential is disproportionally due to one partner, and families react equally strongly to a male and a female relative advantage in educational earnings potential. These results are driven by households with a strong......A unitarian model of family migration in which families may discount wives’ private gains is used to derive testable predictions regarding the type of couples that select into migrating. The empirical tests show that gender neutral family migration cannot be rejected against the alternative...

  16. ILO - International Migration Programme.

    Science.gov (United States)

    Boudraa, Miriam

    2011-01-01

    In a wide International Context characterised not only by the economical development but also by the social, cultural, political and individual development, we witness more and more to a exchange between the developed and the developing countries, which can be translated especially in the migration of the work force. In theory, all countries are either countries of origin either countries of transit or destination, and they are all responsible for the rights of migrant workers by promoting the rights, by monitoring and by preventing the abusive conditions. The process of migration of the workforce can be divided into three stages: the first coincides with the period prior to departure, the second is represented by the aftermath of the departure and the period of stay in the country of destination, the third stage corresponds to the return in the country of origin. The workers must be protected throughout this process by the international organizations that perform the catalytic role of communication and exchange between countries, for the only purpose of protecting the rights of immigrant and/or immigrants workers. The responsibility for the protection of workers is divided among the various players in the International Labour Organisation. Every country has to apply measures according to the international standards regarding workers' rights, standards that guide the various countries in the formulation and implementation of their policies and legislation. These standards are suggested by International Conventions, the ILO Conventions and other international instruments such as the human rights instrument. There has been a big step forward once the ILO Fundamental Conventions and Conventions on Migrant Workers where implemented and this implementation represented the use of the Guidelines "ILO Multilateral Framework on Labour Migration".

  17. Rural migration in Nevada: Lincoln County

    International Nuclear Information System (INIS)

    Soden, D.L.; Carns, D.E.; Mosser, D.; Conary, J.S.; Ansell, J.P.

    1993-01-01

    The principal objective of this project was to develop insight into the scope of migration of working age Nevadans out of their county of birth; including the collection of data on their skill levels, desire to out or in-migrate, interactions between families of migratory persons, and the impact that the proposed high-level nuclear waste repository at Yucca mountain might have on their individual, and collective, decisions to migrate and return. The initial phase of this project reported here was conducted in 1992 and 1993 in Lincoln County, Nevada, one of the counties designated as ''affected'' by the proposed repository program. The findings suggest that a serious out-migration problem in Lincoln County, and that the Yucca mountain project will likely affect decisions relating to migration patterns in the future

  18. Male out-migration: a factor for the spread of HIV infection among married men and women in rural India.

    Directory of Open Access Journals (Sweden)

    Niranjan Saggurti

    Full Text Available INTRODUCTION: Thus far, the reasons for increasing HIV prevalence in northern and eastern Indian states are unknown. We investigated the role of male out-migration in the spread of human immunodeficiency virus (HIV infection through a case-control study in rural India. METHODS: Currently married men and women were recruited from HIV testing and treatment centers across seven selected districts with high rates of male out-migration in eastern and northern India in 2010 using a case-control study design. Case subjects (men: 595, women: 609 were people who tested HIV seropositive and control subjects (men: 611, women: 600 were those tested HIV seronegative. For each gender, we obtained adjusted odds ratios (AORs and population attributable risks (PARs for migration, and behavioral factors. RESULTS: For men, the prevalence of HIV was significantly higher among those with a migration history (AOR, 4.4; for women, the prevalence of HIV was higher among those with migrant husbands (AOR, 2·3. For both genders, the returned male migration (men: AOR, 3·7; women: AOR, 28 was significantly associated with higher prevalence of HIV infection. The PAR associated with male migration was higher for men (54.5%-68.6% than for women (32·7%-56·9% across the study areas. DISCUSSION: Male out-migration is the most important risk factor influencing the spread of HIV infection in rural areas with high out-migration rates, thereby emphasizing the need for interventions, particularly, for returned migrants and spouses of those migrants.

  19. Classifying Returns as Extreme

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    2014-01-01

    I consider extreme returns for the stock and bond markets of 14 EU countries using two classification schemes: One, the univariate classification scheme from the previous literature that classifies extreme returns for each market separately, and two, a novel multivariate classification scheme tha...

  20. Gender and rural-urban migration in China.

    Science.gov (United States)

    Davin, D

    1996-02-01

    Many men and women in China are migrating in search of better economic opportunities. Young women who migrate to urban centers in search of opportunity may stay away from their home villages for several years. At some point, however, they are likely to return home. This article considers the effect which such circular migration is having upon gender relations in China. The author's argument is presented in sections on China's 1990 census, migration and the sexual division of labor, migration and child care, the influence of returning migrants, the influence of young female returnees, and the fertility of returnees. She speculates that the demands and expectations of young women who return to their villages after spending some time earning high wages in urban areas will be affected by urban norms. While their return may lead to initial conflict, it is likely that the women will retain greater personal autonomy from their urban experience. Their return is also likely to lead to a higher degree of material consumption in the rural areas. Present circular migration in China has the potential to return human and financial resources to the villages, thereby helping to prevent the urban-rural gap between economic, social, cultural, and educational factors from growing even wider.

  1. On bar growth and decay during interannual net offshore migration

    NARCIS (Netherlands)

    Walstra, D.J.R.; Reniers, A.J.H.M.; Ranasinghe, R.; Roelvink, J.A.; Ruessink, B.G.

    2012-01-01

    Multiple bar systems often show a cyclic net offshore directed migration with return periods on the order of years. Generally, a bar is generated near the shoreline, grows in height and width, while migrating offshore before finally decaying at the seaward limit of the surf zone. Based on a

  2. Migration: Pre-Requisite for Rural Economic Regeneration?

    Science.gov (United States)

    Stockdale, Aileen

    2006-01-01

    Migration from and to depopulating areas is related to the prospects for rural economic regeneration. The focus is on whether or not migration processes give rise to the necessary human capital required for successful endogenous development. Data from Scottish case studies pertaining to in-, out- and return migrants are analysed. Only by leaving…

  3. Changing patterns of migration in the Adriatic region.

    Science.gov (United States)

    Schatzer, P

    1988-06-01

    International migration in the Adriatic countries of Albania, Greece, Italy, San Marino, and Yugoslavia is briefly examined using data from official and other published sources. The main types of migratory movements identified by the author within the region are "1) economically motivated migration (legal and clandestine); 2) immigration of refugees for resettlement; 3) immigration with the scope of final resettlement in a third country (transit movements); [and] 4) return migration by former emigrants." excerpt

  4. The Globalisation of migration

    OpenAIRE

    Milan Mesić

    2002-01-01

    The paper demonstrates that contemporary international migration is a constitutive part of the globalisation process. After defining the concepts of globalisation and the globalisation of migration, the author discusses six key themes, linking globalisation and international migration (“global cities”, the scale of migration; diversification of migration flows; globalisation of science and education; international migration and citizenship; emigrant communities and new identities). First, in ...

  5. Lidar 2009 - All Returns

    Data.gov (United States)

    Kansas Data Access and Support Center — LIDAR-derived binary (.las) files containing classified points of all returns. We have 3 classifications Unclassified, Ground, Low points. The average Ground Sample...

  6. Families, children, migration and AIDS.

    Science.gov (United States)

    Haour-Knipe, Mary

    2009-01-01

    Migration is very often a family affair, and often involves children, directly or indirectly. It may give rise to better quality of life for an entire family, or to bitter disappointment, and may also increase vulnerability to HIV and AIDS. This review, carried out for the Joint Learning Initiative on Children and AIDS, links the literature on "migration", on "HIV and AIDS" and on "families". Three themes are sketched: (1) As both HIV prevalence and circular migration increase, former migrant workers affected by AIDS may return to their families for care and support, especially at the end of life, often under crisis conditions. Families thus lose promising members, as well as sources of support. However, very little is known about the children of such migrants. (2) Following patterns of migration established for far different reasons, children may have to relocate to different places, sometimes over long distances, if their AIDS-affected parents can no longer care for them. They face the same adaptation challenges as other children who move, but complicated by loss of parent(s), AIDS stigma, and often poverty. (3) The issue of migrant families living with HIV has been studied to some extent, but mainly in developed countries with a long history of migration, and with little attention paid to the children in such families. Difficulties include involuntary separation from family members, isolation and lack of support, disclosure and planning for children's care should the parent(s) die and differences in treatment access within the same family. Numerous research and policy gaps are defined regarding the three themes, and a call is made for thinking about migration, families and AIDS to go beyond description to include resilience theory, and to go beyond prevention to include care.

  7. To stay or not to stay? Out-migration of immigrants from Denmark

    DEFF Research Database (Denmark)

    Jensen, Peter; Pedersen, Peder J.

    2007-01-01

    A major portion of migration flows are temporary, ending with return migration to the home country or migration to a third country. However, the propensity to return differs according to migrants' countries of origin. This paper presents a discussion of the theoretical approaches to return...... migration and a brief survey of the actual flows in Denmark. We then present a panel data set of immigrants to Denmark covering the years 1986 - 1995 and run a number of logit models where return migration is related to individual background factors. Our research shows significant differences in decisions...... of return depending on country of origin, age at entry, education, and family ties. One of the most important determinants is found to be a migrant's success, or lack thereof, regarding labour market integration. This research suggests that policy instruments such as education, training, and temporary wage...

  8. Planning the future's forests with assisted migration

    Science.gov (United States)

    Mary I. Williams; R. Kasten Dumroese

    2014-01-01

    Studies show that changes in climate may exceed plant adaptation and migration. The mismatch in rates between climate change and plant adaptation and migration will pose significant challenges for practitioners that select, grow, and outplant native tree species. Native tree species and populations that are planted today must meet the climatic challenges that they will...

  9. Migration monitoring with automated technology

    Science.gov (United States)

    Rhonda L. Millikin

    2005-01-01

    Automated technology can supplement ground-based methods of migration monitoring by providing: (1) unbiased and automated sampling; (2) independent validation of current methods; (3) a larger sample area for landscape-level analysis of habitat selection for stopover, and (4) an opportunity to study flight behavior. In particular, radar-acoustic sensor fusion can...

  10. Mobility, return for development and sense of Europe: narratives of Moldavian immigrants returning from the European Union

    Directory of Open Access Journals (Sweden)

    Silvia Marcu

    Full Text Available The article links migration, cross-border mobility and return for development embedded in terms of identity and approach to sense of Europe. Taking into account the global changes in Moldova, the paper examines the perceptions of mobility, return and identity of the Moldovans engaged in emigration in the countries of the European Union (EU. Utilising a multi-discipline approach and an in-depth qualitative interview technique, this article seeks to analyze how mobility and return can support social change and development of the country, and argues that people, who cross EU borders, living through the experience of emigration, acquire a pro-European mentality.

  11. Ecological advantages of partial migration as a conditional strategy.

    Science.gov (United States)

    Vélez-Espino, Luis A; McLaughlin, Robert L; Robillard, Melissa

    2013-05-01

    Partial migration is a widespread phenomenon characterized by migrant and resident forms from the same population. In phenotypically plastic taxa with indeterminate growth, resident and migrant ecophenotypes can differ in size and life history traits in ways expected to maximize fitness in the different habitats they exploit. Studies of partial migration in different taxa have advocated either density-dependence or environmental stochasticity as explanations for partial migration. We used a demographic approach for a virtual Brook Trout population to demonstrate the ecological consequences of partial migration under interacting density dependence and environmental stochasticity. The maintenance of partial migration as a conditional strategy in species/populations where resident and migrant forms exhibit life history asymmetries provides ecological advantages. We show that density-dependent migration is expected to increase population fitness under constant environmental conditions or low environmental variation, but decreases population fitness under high environmental variation. These conditions favor intermediate levels of migration as an advantageous tactic. However, there are threshold rates of return migration below which partial migration is no longer a viable tactic. Our modeling approach also allowed the exploration of the distribution of the population by life stage and habitat in response to the strength of density dependence, costs of migration, and return rates, and demonstrated the importance of the conservation of ecophenotypes in partially migratory populations. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Outward migration may alter population dynamics and income inequality

    Science.gov (United States)

    Shayegh, Soheil

    2017-11-01

    Climate change impacts may drive affected populations to migrate. However, migration decisions in response to climate change could have broader effects on population dynamics in affected regions. Here, I model the effect of climate change on fertility rates, income inequality, and human capital accumulation in developing countries, focusing on the instrumental role of migration as a key adaptation mechanism. In particular, I investigate how climate-induced migration in developing countries will affect those who do not migrate. I find that holding all else constant, climate change raises the return on acquiring skills, because skilled individuals have greater migration opportunities than unskilled individuals. In response to this change in incentives, parents may choose to invest more in education and have fewer children. This may ultimately reduce local income inequality, partially offsetting some of the damages of climate change for low-income individuals who do not migrate.

  13. Return emigration: analysis of the situation through life stories

    Directory of Open Access Journals (Sweden)

    M.R Pino Juste

    2014-11-01

    Full Text Available In the context of the importance presently acquired by return immigration in Spain, in this article a descriptive study around the returned emigrants over 65 years old in Galicia is presented.After a brief theoretical introduction on return migration,the research carried out is developed. In the first place, the methodology used in the investigation which allowed an approach to the point of view of the persons concerned is explained: the biographical method through the technique of life stories. In second term, the specific results of the research are presented. After out lining the profile of the returned emigrant, different categories relating to the migratory project in its different phases have been analyzed: fromits beginning —reasons for emigrating—, in their arrival to destiny—labour activity, adaptation, uprooting, etc.—, to the return—reasons for returning, problems of readjustment to the place of origin, etc.—

  14. The Reference Return Ratio

    DEFF Research Database (Denmark)

    Nicolaisen, Jeppe; Faber Frandsen, Tove

    2008-01-01

    The paper introduces a new journal impact measure called The Reference Return Ratio (3R). Unlike the traditional Journal Impact Factor (JIF), which is based on calculations of publications and citations, the new measure is based on calculations of bibliographic investments (references) and returns...... (citations). A comparative study of the two measures shows a strong relationship between the 3R and the JIF. Yet, the 3R appears to correct for citation habits, citation dynamics, and composition of document types - problems that typically are raised against the JIF. In addition, contrary to traditional...

  15. The Returns to Entrepreneurship

    DEFF Research Database (Denmark)

    Van Praag, Mirjam; Raknerud, Arvid

    Empirical studies show low pecuniary returns of switching from wage employment to entrepreneurship. We reconsider the pecuniary gains of this switching by employing a two-stage procedure, where the randomness in the timing of inheritance transfers is used as an exclusion restriction to identify...... causal effects. The model is estimated on data covering the whole Norwegian population of individuals matched to the entire population of firms established in the period 2002-2011. The results indicate that the average returns to entrepreneurship are significantly negative for individuals entering...... entrepreneurship through self-employment and modest, but significantly positive, for incorporated startups....

  16. Return to nucleate boiling

    International Nuclear Information System (INIS)

    Shumway, R.W.

    1985-01-01

    This paper presents a collection of TMIN (temperature of return to nucleate boiling) correlations, evaluates them under several conditions, and compares them with a wide range of data. Purpose is to obtain the best one for use in a water reactor safety computer simulator known as TRAC-B. Return to nucleate boiling can occur in a reactor accident at either high or low pressure and flow rates. Most of the correlations yield unrealistic results under some conditions. A new correlation is proposed which overcomes many of the deficiencies

  17. Dynamics of urban population growth in Nigeria: The role of repeated migration.

    Science.gov (United States)

    Adepoju, A

    1976-02-01

    The paper examines the direct contribution of migration to the growth of the urban population both in terms of its mobility and stability components with special reference to Western Nigeria. The basis of the paper is a survey of urban migration conducted by the author in 1971-1972; the findings are supplemented where necessary by the 1952-1953 and 1963 census figures. Migration is a major factor in the growth of the urban population. The direct contribution by migrants to such growth can be traced to the following groups: the initial streams of migrants, the follow-up migrants and the potentially mobile migrants attracted from the migrants' communities of origin to the towns. Repeated migration by some migrants, particularly the young, the educated and the white collar-workers, are also major factors in the urban population growth. Such repeated migrations are predominantly urban to urban or turnover moves. The high mobility rate among a group of migrants tends to conceal the relative stability among the migrant population as a whole. Repeated migrants usually stay between 3 and 5 years at each destination, before moving on. A substantial proportion of migrants, mainly farmers, the less educated and the old, are relatively stable in the survey towns (Ife and Oshogho). The urban residence ration indices also indicate an increase in the rate of immigration, mainly of young persons, to the towns. The youthful age structure, the age selectivity in migration and the marital status of the young migrants tend to exacerbate the masculinity in the form of unbalanced sex ratio prevailing in most urban centers. The urban population is unlikely to be stable. The tendency for old migrants of rural origin to return to their villages at the end of their migration career and for contemporary migrants to consist predominantly of youths, will for the next generation or 2 lead to a young and unstable urban population.

  18. Sustainable Mars Sample Return

    Science.gov (United States)

    Alston, Christie; Hancock, Sean; Laub, Joshua; Perry, Christopher; Ash, Robert

    2011-01-01

    The proposed Mars sample return mission will be completed using natural Martian resources for the majority of its operations. The system uses the following technologies: In-Situ Propellant Production (ISPP), a methane-oxygen propelled Mars Ascent Vehicle (MAV), a carbon dioxide powered hopper, and a hydrogen fueled balloon system (large balloons and small weather balloons). The ISPP system will produce the hydrogen, methane, and oxygen using a Sabatier reactor. a water electrolysis cell, water extracted from the Martian surface, and carbon dioxide extracted from the Martian atmosphere. Indigenous hydrogen will fuel the balloon systems and locally-derived methane and oxygen will fuel the MAV for the return of a 50 kg sample to Earth. The ISPP system will have a production cycle of 800 days and the estimated overall mission length is 1355 days from Earth departure to return to low Earth orbit. Combining these advanced technologies will enable the proposed sample return mission to be executed with reduced initial launch mass and thus be more cost efficient. The successful completion of this mission will serve as the next step in the advancement of Mars exploration technology.

  19. Higher Education Endowments Return

    Science.gov (United States)

    Bahlmann, David; Walda, John D.; Sedlacek, Verne O.

    2012-01-01

    A new study of endowments by the National Association of College and University Business Officers (NACUBO) and the Commonfund Institute has brought good news to college and universities: While endowment returns dropped precipitously in fiscal year 2009 as a result of the financial crisis and accompanying slide in equity markets, they climbed to an…

  20. Return to Play

    Science.gov (United States)

    Mangan, Marianne

    2013-01-01

    Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

  1. Using stochastic gradient boosting to infer stopover habitat selection and distribution of Hooded Cranes Grus monacha during spring migration in Lindian, Northeast China.

    Science.gov (United States)

    Cai, Tianlong; Huettmann, Falk; Guo, Yumin

    2014-01-01

    The Hooded Crane (Grus monacha) is a globally vulnerable species, and habitat loss is the primary cause of its decline. To date, little is known regarding the specific habitat needs, and stopover habitat selection in particular, of the Hooded Crane. In this study we used stochastic gradient boosting (TreeNet) to develop three specific habitat selection models for roosting, daytime resting, and feeding site selection. In addition, we used a geographic information system (GIS) combined with TreeNet to develop a species distribution model. We also generated a digital map of the relative occurrence index (ROI) of this species at daytime resting sites in the study area. Our study indicated that the water depth, distance to village, coverage of deciduous leaves, open water area, and density of plants were the major predictors of roosting site selection. For daytime resting site selection, the distance to wetland, distance to farmland, and distance to road were the primary predictors. For feeding site selection, the distance to road, quantity of food, plant coverage, distance to village, plant density, distance to wetland, and distance to river were contributing factors, and the distance to road and quantity of food were the most important predictors. The predictive map showed that there were two consistent multi-year daytime resting sites in our study area. Our field work in 2013 using systematic ground-truthing confirmed that this prediction was accurate. Based on this study, we suggest that Lindian plays an important role for migratory birds and that cultivation practices should be adjusted locally. Furthermore, public education programs to promote the concept of the harmonious coexistence of humans and cranes can help successfully protect this species in the long term and eventually lead to its delisting by the IUCN.

  2. Using stochastic gradient boosting to infer stopover habitat selection and distribution of Hooded Cranes Grus monacha during spring migration in Lindian, Northeast China.

    Directory of Open Access Journals (Sweden)

    Tianlong Cai

    Full Text Available The Hooded Crane (Grus monacha is a globally vulnerable species, and habitat loss is the primary cause of its decline. To date, little is known regarding the specific habitat needs, and stopover habitat selection in particular, of the Hooded Crane. In this study we used stochastic gradient boosting (TreeNet to develop three specific habitat selection models for roosting, daytime resting, and feeding site selection. In addition, we used a geographic information system (GIS combined with TreeNet to develop a species distribution model. We also generated a digital map of the relative occurrence index (ROI of this species at daytime resting sites in the study area. Our study indicated that the water depth, distance to village, coverage of deciduous leaves, open water area, and density of plants were the major predictors of roosting site selection. For daytime resting site selection, the distance to wetland, distance to farmland, and distance to road were the primary predictors. For feeding site selection, the distance to road, quantity of food, plant coverage, distance to village, plant density, distance to wetland, and distance to river were contributing factors, and the distance to road and quantity of food were the most important predictors. The predictive map showed that there were two consistent multi-year daytime resting sites in our study area. Our field work in 2013 using systematic ground-truthing confirmed that this prediction was accurate. Based on this study, we suggest that Lindian plays an important role for migratory birds and that cultivation practices should be adjusted locally. Furthermore, public education programs to promote the concept of the harmonious coexistence of humans and cranes can help successfully protect this species in the long term and eventually lead to its delisting by the IUCN.

  3. Migratory connectivity of american woodcock using band return data

    Science.gov (United States)

    Moore, Joseph D.; Krementz, David G.

    2017-01-01

    American woodcock (Scolopax minor) are managed as a Central and an Eastern population in the United States and Canada based on band return data showing little crossover between populations or management regions. The observed proportion of crossover between management regions, however, depends on the criteria used to subset the band return data. We analyzed the amount of crossover between management regions using only band return records that represent complete migrations between the breeding and wintering grounds by using only band return records in which the capture took place during the breeding season and the band recovery took place during the wintering season or vice versa (n = 224). Additionally, we applied spatial statistics and a clustering algorithm to investigate woodcock migratory connectivity using this subset of migratory woodcock band return records. Using raw counts, 17.9% of records showed crossover between management regions, a higher proportion than the <5% crossover reported in studies that did not use only migratory band returns. Our results showed woodcock from the breeding grounds in the Central Region largely migrate to destinations within the Central Region, whereas woodcock from the breeding grounds in the Eastern Region migrate to destinations across the entire wintering range and mix with individuals from the Central Region. Using the division coefficient, we estimated that 54% of woodcock from the breeding grounds of the Eastern Region migrate to the Central Region wintering grounds. Our result that many woodcock from separate regions of the breeding grounds mix on the wintering grounds has implications for the 2-region basis for woodcock management. Elucidating finer scale movement patterns among regions provides a basis for reassessing the need for separate management regions to ensure optimal conservation and management of the species.

  4. Reabsorption of returning workers from the Gulf: the Asian experience.

    Science.gov (United States)

    Kazi, S

    1994-01-01

    This study examines trends in return labor migration from the Middle East to South Asia and Southeast Asia. Survey data were used to describe trends in outmigration and socioeconomic characteristics of return migrants and to examine the extent to which return migration is associated with skill level and use of savings and remittances on their return. General trends indicate a decline in outmigration during the late 1980s and early 1990s, after oil prices dropped in 1986. Migrants from Pakistan and Korea declined by half during 1981-85 and by 40% among Indian migrants. The demand for service workers and migrants willing to accept cuts in wages was unaffected. Outmigration from Southeast Asian countries grew in the recent past. These increases were due to the replacement of workers from Jordan and Yemen who were expelled from Saudi Arabia after the Gulf crisis. The shift in occupational demand to service and higher level workers is expected to weaken migration from Pakistan and Bangladesh and to strengthen migration from Sri Lanka and other Southeast Asian countries with a skilled migrant labor force. Outmigration from Southeast Asian countries increased to high-growth destination countries such as Japan, Malaysia, and Singapore. Socioeconomic characteristics of migrants varied by country of origin. For instance, Philippine migrants were better educated. Migrants from Thailand, Bangladesh, and Pakistan were from rural and impoverished areas. Sri Lanka and the Philippines had many women migrants. Return migrants encountered high unemployment. Return migrants to Korea had fewer reemployment problems. Reemployment was associated with local country conditions. Unskilled workers had the highest rates of unemployment. Savings tended to be invested in real estate and housing. Savings and investment from remittance income was high in Sri Lanka, Bangladesh, and Thailand.

  5. [Haitian migration to Santo Domingo].

    Science.gov (United States)

    Latortue, P R

    1985-01-01

    explained migration of unskilled labor from poorer countries in more than 1 case. Under such circumstances, the extremely poor working conditions of Haitians in the Dominican Republic are not surprising. A 1983 investigation by the International Labour Organization indicated that salaries were low, that a large proportion was routinely diverted from the migrants, that hours of work were long with no regular rest and few days off, that few workers had any contractual protection, that forced labor recruitment occurred, that a rigid system of vigilance with armed patrols was used to keep the immigrants in the work camps, and that living conditions were substandard--in short, that Haitian workers were "neo-slaves". In addition, the Dominicans consider themselves racially and culturally superior to Haitians. The Haitian government, in return for payments from the Dominican Republic, does nothing to stop the abuses.

  6. The migration game in habitat network: the case of tuna

    DEFF Research Database (Denmark)

    Mariani, Patrizio; Krivan, Vlastimil; MacKenzie, Brian

    2016-01-01

    migration in direction of increasing fitness should lead to the ideal free distribution (IFD) which is the evolutionary stable strategy of the habitat selection game. We introduce a migration game which focuses on migrating dynamics leading to the IFD for age-structured populations and in time varying...

  7. Returning to the homeland: The migratory patterns between Brazil and Japan for Japanese-Brazilians

    Directory of Open Access Journals (Sweden)

    Yoko Baba

    2012-04-01

    Full Text Available Migration to well-off countries has been well documented. However, the reasons why migrants return to their home countries, which often face severe economic disadvantages, are examined less frequently. The return migration ofJapanese-Brazilians (Brazilian citizens of ethnic Japanese descent who migrate to Japan and return again to Brazil has not been studied to any great extent. To understand the factors associated with Japanese-Brazilians’ return migration, using Gmelch's (1983 model of push and pull factors, we examined what motivated Japanese-Brazilian migrant laborers to return to Brazil from Japan.With a mixed method including in-person interviews, a total of n=47 Brazilian migrants to Japan were sampled in São Paulo, Brazil. The present examination resulted in a pattern similar to the one Gmelch (1983 observed in his study on Irish and Newfoundlander return migrants. In the current study, pull factors were more important than push factors in terms of repatriation. Personal and social pull factors were stronger reasons compelling migrants return to Brazil than were economic or familial factors. Nevertheless, familial and economic reasons were also reported as important motivators for returning to Brazil in our interviews. Limitations are also discussed.

  8. Chemotherapeutic agents attenuate CXCL12-mediated migration of colon cancer cells by selecting for CXCR4-negative cells and increasing peptidase CD26

    International Nuclear Information System (INIS)

    Cutler, Murray J.; Lowthers, Erica L.; Richard, Cynthia L.; Hajducek, Dagmar M.; Spagnuolo, Paul A.; Blay, Jonathan

    2015-01-01

    Recurrence of colorectal cancer (CRC) may arise due to the persistence of drug-resistant and cancer-initiating cells that survive exposure to chemotherapy. Proteins responsible for this recurrence include the chemokine receptor CXCR4, which is known to enable CRC metastasis, as well as the cancer-initiating cell marker and peptidase CD26, which terminates activity of its chemokine CXCL12. We evaluated the expression and function of CXCR4 and CD26 in colon cancer cell lines and xenografts following treatment with common chemotherapies using radioligand binding, flow cytometry, immunofluorescence, and enzymatic assays. 5-Fluorouracil, oxaliplatin and SN-38 (the active metabolite of irinotecan), as well as cisplatin, methotrexate and vinblastine, each caused decreases in cell-surface CXCR4 and concomitant increases in CD26 on HT-29, T84, HRT-18, SW480 and SW620 CRC cell lines. Flow cytometry indicated that the decline in CXCR4 was associated with a significant loss of CXCR4+/CD26- cells. Elevations in CD26 were paralleled by increases in both the intrinsic dipeptidyl peptidase activity of CD26 as well as its capacity to bind extracellular adenosine deaminase. Orthotopic HT-29 xenografts treated with standard CRC chemotherapeutics 5-fluorouracil, irinotecan, or oxaliplatin showed dramatic increases in CD26 compared to untreated tumors. Consistent with the loss of CXCR4 and gain in CD26, migratory responses to exogenous CXCL12 were eliminated in cells pretreated with cytotoxic agents, although cells retained basal motility. Analysis of cancer-initiating cell CD44 and CD133 subsets revealed drug-dependent responses of CD26/CD44/CD133 populations, suggesting that the benefits of combining standard chemotherapies 5-fluoruracil and oxaliplatin may be derived from their complementary elimination of cell populations. Our results indicate that conventional anticancer agents may act to inhibit chemokine-mediated migration through eradication of CXCR4+ cells and attenuation of

  9. Product return management

    DEFF Research Database (Denmark)

    Shaharudin, Mohd Rizaimy; Govindan, Kannan; Zailani, Suhaiza

    2017-01-01

    The aim of this study is to examine the extent to which product returns motivate manufacturing firms to adopt closed-loop supply chain activities that influence the effectiveness of reverse supply chains. The hypotheses have been tested using data from a sample of 150 environmental management...... system ISO 14001 certified manufacturing firms in Malaysia through the census sampling approach. The results of the empirical test using LISREL Version 8.70 for the structural equation modeling support the fundamental explanation of the influence of the institutional forces towards the adoption of closed...... eventually impacts the firm's effectiveness in the reverse supply chain. The findings also help managers to understand the factors that can improve the outcome of the adoption of closed-loop supply chain activities by intensifying the extent of involvement in product returns, which provides a valuable...

  10. MANAGING MIGRATION: TURKISH PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    İhsan GÜLAY

    2018-04-01

    Full Text Available Conducting migration studies is of vital importance to Turkey, a country which has been experiencing migration throughout history due to its “open doors policy”. The objective of this study is to evaluate the strategic management of migration in Turkey in order to deal with the issue of migration. The main focus of the study is Syrian migrants who sought refuge in Turkey due to the civil war that broke out in their country in April 2011. This study demonstrates the policies and processes followed by Turkey for Syrian migration flow in terms of the social acceptance and harmonisation of the migrants within a democratic environment. The study addresses some statistical facts and issues related to Syrian migration as it has become an integral part of daily life in Turkey. The study also reviews how human rights are protected in the migration process. The study will provide insights for developing sound strategic management policies for the migration issue.

  11. Migration and revolution

    Directory of Open Access Journals (Sweden)

    Nando Sigona

    2012-06-01

    Full Text Available The Arab Spring has not radically transformed migration patterns in the Mediterranean, and the label ‘migration crisis’ does not do justice to the composite and stratified reality.

  12. [Internal migration studies].

    Science.gov (United States)

    Stpiczynski, T

    1986-10-01

    Recent research on internal migration in Poland is reviewed. The basic sources of data, consisting of censuses or surveys, are first described. The author discusses the relationship between migration studies and other sectors of the national economy, and particularly the relationship between migration and income.

  13. Juridical structures: refugees and migration.

    Science.gov (United States)

    Veiter, T

    1988-01-01

    The juridical problems in regard to the concepts of refugee, expulsion, and migration are complicated. If one speaks about migration in Europe, one must 1st distinguish between Eastern and Western Europe. In the communist states of Eastern Europe the refugee problem does not exist officially, with the only existing refugee problem in Yugoslavia, which has signed and ratified the Geneva Refugee Convention of 1951. In the other East European states the right to asylum exists, but refugees are granted asylum only if they are persecuted in their country of origin for their communist ideas and activities. In speaking of migration, one must distinguish between migration, forced migration, mass migration, emigration, immigration, the shift of populations, and refugees. In the communist countries of Eastern Europe the right to emigration is not respected, although certain exceptions, as in Poland or Yugoslavia do exist. Generally, in the communist states emigration is not allowed and illegal emigration is punished as "Flight from the Republic." With a few exceptions, political and other persecutions are no longer so typical within Europe. In the last decades, the refugee problem has changed to other continents: Afghanistan/Pakistan, Iran, Sri Lanka, East Timor, Lebanon, Palestine, Sudan, Tchad, Ethiopia, Eritrea, and Angola. The refugee problem in Europe consists mainly in the large afflux of refugees coming from places with other cultural (and religious) attributes. The Islamic immigrants declare themselves regularly as political refugees and hope to be acknowledged as such by the receiving state. The fear of the governments and populations of the receiving countries is that it would not be possible to assimilate such aliens who do not belong to the Christian culture of Europe. Formerly, refugees came mostly from the Christian countries of Eastern Europe with the same race identity and the same religion. For years now, more and more foreign workers are a kind of migrant

  14. Mars Sample Return Architecture Overview

    Science.gov (United States)

    Edwards, C. D.; Vijendran, S.

    2018-04-01

    NASA and ESA are exploring potential concepts for a Sample Retrieval Lander and Earth Return Orbiter that could return samples planned to be collected and cached by the Mars 2020 rover mission. We provide an overview of the Mars Sample Return architecture.

  15. The commodification of international migration: findings from Thailand.

    Science.gov (United States)

    Jones, H; Pardthaisong, T

    1999-01-01

    "The organisation of international contract-labour migration within Asia has been increasingly dominated by commercial agencies acting as intermediaries between workers and foreign employers. The principles underpinning the gatekeeping role of such agencies in the East Asian migration system are examined. A consideration of the international labour recruitment system in Thailand is based on survey work among agents, community leaders and recently returned migrants." excerpt

  16. "International Migration and Gender Discrimination among Children Left Behind"

    Science.gov (United States)

    Antman, Francisca M

    2011-05-01

    This paper considers how international migration of the head of household affects the allocation of resources toward boys relative to girls within households remaining in the home country. I address the endogeneity of migration with a differences-in-differences style regression model that compares those households in which migrants have already returned home with those in which migrants are still away. The evidence suggests that while the head of household is away a greater fraction of resources are spent on girls relative to boys, but upon his return, this pattern is reversed.

  17. Intra-household tensions and conflicts of interest in migration decision making: a case study of the Todgha valley, Morocco

    NARCIS (Netherlands)

    de Haas, H.; Fokkema, C.M.

    2009-01-01

    This paper explores the role of intra-household tensions and conflicts of interest in explaining the diverse return and pendulum migration strategies among Moroccan migrants who first migrated to Europe in the 1960s and 1970s. Migration strategies and motivations of migrants and their households are

  18. Morphological constraints on changing avian migration phenology.

    Science.gov (United States)

    Møller, A P; Rubolini, D; Saino, N

    2017-06-01

    Many organisms at northern latitudes have responded to climate warming by advancing their spring phenology. Birds are known to show earlier timing of spring migration and reproduction in response to warmer springs. However, species show heterogeneous phenological responses to climate warming, with those that have not advanced or have delayed migration phenology experiencing population declines. Although some traits (such as migration distance) partly explain heterogeneity in phenological responses, the factors affecting interspecies differences in the responsiveness to climate warming have yet to be fully explored. In this comparative study, we investigate whether variation in wing aspect ratio (reflecting relative wing narrowness), an ecomorphological trait that is strongly associated with flight efficiency and migratory behaviour, affects the ability to advance timing of spring migration during 1960-2006 in a set of 80 European migratory bird species. Species with larger aspect ratio (longer and narrower wings) showed smaller advancement of timing of spring migration compared to species with smaller aspect ratio (shorter and wider wings) while controlling for phylogeny, migration distance and other life-history traits. In turn, migration distance positively predicted aspect ratio across species. Hence, species that are better adapted to migration appear to be more constrained in responding phenologically to rapid climate warming by advancing timing of spring migration. Our findings corroborate the idea that aspect ratio is a major evolutionary correlate of migration, and suggest that selection for energetically efficient flights, as reflected by high aspect ratio, may hinder phenotypically plastic/microevolutionary adjustments of migration phenology to ongoing climatic changes. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  19. A probe into reasons for international migration in Fujian Province.

    Science.gov (United States)

    Zhu, G

    1990-01-01

    In this paper, the author discusses the extent of international migration from China's Fujian Province and considers the reasons behind the migration. The most recent estimates place China's overseas population at 22.1 million, 19 million (88%) of which are concentrated in Southeast Asia. According to the author's calculations, at least 7 million of the Chinese overseas population are of Fujian descent. Indonesia alone holds some 3.3 million Fujianese. Malaysia, Singapore, and the Philippines account for most of the remaining Fujianese overseas population. Having established the extent of international migration from the Fujian Province, the author attempts to establish the reasons behind it. The author first considers the historical origins of Fujianese international migration, from its early states (end century B.C.-17th century) to modern times *18-early 20th century) to the current period (1949-present). The author then examines the reasons behind the migration, primarily the social environment and individual behavior. Finally, the author provides categories of international migration, stressing that these categories often overlap or coincide. Most of the early migration was "spontaneous" -- essentially, an unplanned occurrence. During the modern period, most migration was "forced" by the contract labor system instituted by colonialists. Political and social upheaval also prompted "provoked" international migration. And following the Chinese Revolution, "free" migration allowed many to return home or to join relative abroad.

  20. The interrelationship of fertility, family maintenance and Mexico-U.S. Migration

    Directory of Open Access Journals (Sweden)

    Silvia Giorguli Saucedo

    2007-12-01

    Full Text Available This study examines the interrelationship between migration and marital fertility, using a bi-national sample of retrospective life histories collected in Mexican origin communities and U.S. destination areas. We treat couples as the unit of analysis and use discrete-time hazard models to examine: (1 how the timing and parity of births influence the occurrence of migration (to the U.S. or return to Mexico and the type of migration (solo or couple, and (2 how current migration status and cumulative migration experience influence the likelihood of a birth. Examining the effects of fertility on migration, and the effects of migration on the timing of births, we are able to address how couples integrate migration opportunities and fertility goals into family building strategies in a context where international circular migration is pervasive.

  1. Automation of Flexible Migration Workflows

    Directory of Open Access Journals (Sweden)

    Dirk von Suchodoletz

    2011-03-01

    Full Text Available Many digital preservation scenarios are based on the migration strategy, which itself is heavily tool-dependent. For popular, well-defined and often open file formats – e.g., digital images, such as PNG, GIF, JPEG – a wide range of tools exist. Migration workflows become more difficult with proprietary formats, as used by the several text processing applications becoming available in the last two decades. If a certain file format can not be rendered with actual software, emulation of the original environment remains a valid option. For instance, with the original Lotus AmiPro or Word Perfect, it is not a problem to save an object of this type in ASCII text or Rich Text Format. In specific environments, it is even possible to send the file to a virtual printer, thereby producing a PDF as a migration output. Such manual migration tasks typically involve human interaction, which may be feasible for a small number of objects, but not for larger batches of files.We propose a novel approach using a software-operated VNC abstraction layer in order to replace humans with machine interaction. Emulators or virtualization tools equipped with a VNC interface are very well suited for this approach. But screen, keyboard and mouse interaction is just part of the setup. Furthermore, digital objects need to be transferred into the original environment in order to be extracted after processing. Nevertheless, the complexity of the new generation of migration services is quickly rising; a preservation workflow is now comprised not only of the migration tool itself, but of a complete software and virtual hardware stack with recorded workflows linked to every supported migration scenario. Thus the requirements of OAIS management must include proper software archiving, emulator selection, system image and recording handling. The concept of view-paths could help either to automatically determine the proper pre-configured virtual environment or to set up system

  2. Les questions de migrations internationales

    Science.gov (United States)

    Samman, Mouna Liliane

    1993-03-01

    International migrations have growing implications for both countries of origin and countries of destination. In the latter, the presence of foreigners and of members of their families today creates problems of integration, causes argument and brings mounting xenophobia. Paralleling political, economic and social measures taken by public authorities to respond to these difficulties, education needs to assist in defusing the resulting social tensions by preparing the minds of learners and helping to develop new attitudes. In particular, when educational programmes address questions of international migration, these should be treated in the framework of historical evolution so that their real significance and their true temporal and spatial dimensions become apparent. It is also important that the growing interdependence between countries should be made plain, that national history should be placed in its international context, and that the true consequences of these developments should be made clear. In this context, learners need to be acquainted with Human Rights, thereby stressing universal moral values and the role of the individual. Lastly, questions relating to international migration are usually presented in the media in a selective and partial manner, and the young people who take in this information often accept the hasty judgments which are made of situations as proven facts. This is why all teaching about international migration needs to be considered or reconsidered in the light of the complementary or competing actions of the media.

  3. The Return to Foreign Aid

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Hansen, Henrik

    2017-01-01

    We estimate the average rate of return on investments financed by aid and by domestic resource mobilisation, using aggregate data. Both returns are expected to vary across countries and time. Consequently we develop a correlated random coefficients model to estimate the average returns. Across...... different estimators and two different data sources for GDP and investment our findings are remarkably robust; the average gross return on ‘aid investments’ is about 20 per cent. This is in accord with micro estimates of the economic rate of return on aid projects and with aggregate estimates of the rate...

  4. The consequences of Ireland's culture of medical migration.

    Science.gov (United States)

    Humphries, Niamh; Crowe, Sophie; McDermott, Cian; McAleese, Sara; Brugha, Ruairi

    2017-12-28

    In recent years, Ireland has experienced a large-scale, outward migration of doctors. This presents a challenge for national policy makers and workforce planners seeking to build a self-sufficient medical workforce that trains and retains enough doctors to meet demand. Although, traditionally, medical migration has been considered beneficial to the Irish health system, austerity has brought a greater level of uncertainty to the health system and, with it, a need to reappraise the professional culture of migration and its impact on the Irish health system. This paper illustrates how a culture of migration informs career and migration plans. It draws on quantitative data-registration and migration data from source and destination countries-and qualitative data-in-depth interviews with 50 doctors who had undertaken postgraduate medical training in Ireland. Of 50 respondents, 42 highlighted the importance of migration. The culture of medical migration rests on two assumptions-that international training/experience is beneficial to all doctors and that those who emigrate will return to Ireland with additional skills and experience. This assumption of return is challenged by a new generation of doctors whose professional lives have been shaped by globalisation and by austerity. Global comparisons reveal the comparatively poor working conditions, training and career opportunities in Ireland and the relative attractiveness of a permanent career abroad. In light of these changes, there is a need to critically appraise the culture of medical migration to determine if and in what circumstances migration is appropriate to the needs of the Irish health system. The paper considers the need to reappraise the culture of medical migration and the widespread emigration that it promotes.

  5. Impact Of Monetary Policy On Financial Asset Returns: An Analysis ...

    African Journals Online (AJOL)

    Impact Of Monetary Policy On Financial Asset Returns: An Analysis Of Selected Stocks From The Nigerian Capital Market. ... Journal of Research in National Development. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current ...

  6. Radon depth migration

    International Nuclear Information System (INIS)

    Hildebrand, S.T.; Carroll, R.J.

    1993-01-01

    A depth migration method is presented that used Radon-transformed common-source seismograms as input. It is shown that the Radon depth migration method can be extended to spatially varying velocity depth models by using asymptotic ray theory (ART) to construct wavefield continuation operators. These operators downward continue an incident receiver-array plane wave and an assumed point-source wavefield into the subsurface. The migration velocity model is constrain to have longer characteristic wavelengths than the dominant source wavelength such that the ART approximations for the continuation operators are valid. This method is used successfully to migrate two synthetic data examples: (1) a point diffractor, and (2) a dipping layer and syncline interface model. It is shown that the Radon migration method has a computational advantage over the standard Kirchhoff migration method in that fewer rays are computed in a main memory implementation

  7. San Francisco Estuary Striped Bass Migration History Determined by Electron-microprobe Analysis of Otolith Sr/Ca Ratio

    Energy Technology Data Exchange (ETDEWEB)

    Ostrach, D J; Phillis, C C; Weber, P K; Ingram, B L; Zinkl, J G

    2004-09-17

    Habitat use has been shown to be an important factor in the bioaccumulation of contaminants in striped bass. This study examines migration in striped bass as part of a larger study investigating bioaccumulation and maternal transfer of xenobiotics to progeny in the San Francisco Estuary system. Habitat use, residence time and spawning migration over the life of females (n = 23) was studied. Female striped bass were collected between Knights Landing and Colusa on the Sacramento River during the spawning runs of 1999 and 2001. Otoliths were removed, processed and aged via otolith microstructure. Subsequently, otoliths were analyzed for strontium/calcium (Sr/Ca) ratio using an electron-microprobe to measure salinity exposure and to distinguish freshwater, estuary, and marine habitat use. Salinity exposure during the last year before capture was examined more closely for comparison of habitat use by the maternal parent to contaminant burden transferred to progeny. Results were selectively confirmed by ion microprobe analyses for habitat use. The Sr/Ca data demonstrate a wide range of migratory patterns. Age of initial ocean entry differs among individuals before returning to freshwater, presumably to spawn. Some fish reside in freshwater year-round, while others return to more saline habitats and make periodic migrations to freshwater. Frequency of habitat shifts and residence times differs among fish, as well as over the lifetime of individual fish. While at least one fish spent its final year in freshwater, the majority of spawning fish spent their final year in elevated salinity. However, not all fish migrated to freshwater to spawn in the previous year. Results from this investigation concerning migration history in striped bass can be combined with contaminant and histological developmental analyses to better understand the bioaccumulation of contaminants and the subsequent effects they and habitat use have on fish populations in the San Francisco Estuary system.

  8. Migration into art

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    This book addresses a topic of increasing importance to artists, art historians and scholars of cultural studies, migration studies and international relations: migration as a profoundly transforming force that has remodelled artistic and art institutional practices across the world. It explores...... contemporary art's critical engagement with migration and globalisation as a key source for improving our understanding of how these processes transform identities, cultures, institutions and geopolitics. The author explores three interwoven issues of enduring interest: identity and belonging, institutional...

  9. Estimating the Ex Ante Expected Returns to College

    OpenAIRE

    Andrew J. Hussey; Omari H. Swinton

    2011-01-01

    Rather than estimating the returns to obtaining a college degree, this paper treats the college education decision as an uncertain investment involving varying likelihoods of successful graduation. We predict earnings conditional on both graduating and not graduating from both selective and non-selective institutions, and incorporate estimated individual-specific graduation rates in calculating the ex ante expected returns from college attendance for individuals across the ability distributio...

  10. Regional Redistribution and Migration

    DEFF Research Database (Denmark)

    Manasse, Paolo; Schultz, Christian

    We study a model with free migration between a rich and a poor region. Since there is congestion, the rich region has an incentive to give the poor region a transfer in order to reduce immigration. Faced with free migration, the rich region voluntarily chooses a transfer, which turns out...... to be equal to that a social planner would choose. Provided migration occurs in equilibrium, this conclusion holds even in the presence of moderate mobility costs. However, large migration costs will lead to suboptimal transfers in the market solution...

  11. Computing return times or return periods with rare event algorithms

    Science.gov (United States)

    Lestang, Thibault; Ragone, Francesco; Bréhier, Charles-Edouard; Herbert, Corentin; Bouchet, Freddy

    2018-04-01

    The average time between two occurrences of the same event, referred to as its return time (or return period), is a useful statistical concept for practical applications. For instance insurances or public agencies may be interested by the return time of a 10 m flood of the Seine river in Paris. However, due to their scarcity, reliably estimating return times for rare events is very difficult using either observational data or direct numerical simulations. For rare events, an estimator for return times can be built from the extrema of the observable on trajectory blocks. Here, we show that this estimator can be improved to remain accurate for return times of the order of the block size. More importantly, we show that this approach can be generalised to estimate return times from numerical algorithms specifically designed to sample rare events. So far those algorithms often compute probabilities, rather than return times. The approach we propose provides a computationally extremely efficient way to estimate numerically the return times of rare events for a dynamical system, gaining several orders of magnitude of computational costs. We illustrate the method on two kinds of observables, instantaneous and time-averaged, using two different rare event algorithms, for a simple stochastic process, the Ornstein–Uhlenbeck process. As an example of realistic applications to complex systems, we finally discuss extreme values of the drag on an object in a turbulent flow.

  12. The role of family network in circular migration and formation of transnational communities

    DEFF Research Database (Denmark)

    Rezaei, Shahamak; Marques, Denise Helena França

    2016-01-01

    The complexity of family arrangements that constitute the return migration of Brazilians from Paraguay can be identified as an important element in maintaining the circularity between the two countries and the consolidation of transnational space Brasiguaio. This paper describes the changes in vo....... Information from the Brazilian Demographic Censuses of 1991, 2000 and 2010 will be used to do so, and to estimate the direct and indirect effects of international migration return to that country....

  13. The migration of doctors and nurses from South Pacific Island Nations.

    Science.gov (United States)

    Brown, Richard P C; Connell, John

    2004-06-01

    Little is known of the structure of the international migration of skilled health professionals. Accelerated migration of doctors and nurses from the Pacific island states of Fiji, Samoa and Tonga to the Pacific periphery is part of the globalization of health care. The findings from a recent survey of 251 doctors and nurses from the three island countries are reported here. Key determinants of both present migration status and future migration intentions were analyzed using econometric methods. Nurses' and doctors' propensities to migrate are influenced by both income and non-income factors, including ownership of businesses and houses. Migrants also tend to have more close relatives overseas, to have trained there, and so experienced superior working conditions. Migration propensities vary between countries, and between nurses and doctors within countries. Tongan nurses have a higher propensity to migrate, mainly because of greater relative earnings differentials, but are also more likely to return home. The role of kinship ties, relative income differentials and working conditions is evident in other developing country contexts. Remittances and return migration, alongside business investment, bring some benefits to compensate for the skill drain. National development policies should focus on encouraging return migration, alongside retention and recruitment, but are unlikely to prevent out migration.

  14. Social effects of migration in receiving countries.

    Science.gov (United States)

    Ohndorf, W

    1989-06-01

    This paper examines the impact of post-1945 migration into Western, Middle, and Northern Europe from Southern Europe, Turkey, and Northern Africa, and migration to the traditional immigration countries by Asian and Latin American immigrants, on the social structures of receiving countries. Between 1955 and 1974, 1) traditional migration to the US and Australia became less important for European countries while traditional receiving countries accepted many immigrants from developing countries; and 2) rapid economic revival in Western and Northern Europe caused a considerable labor shortage which was filled by migrant workers especially from Southern Europe, Turkey, and Northern Africa, who stayed only until they reached their economic goals. Since 1974, job vacancies have declined and unemployment has soared. This employment crisis caused some migrants 1) to return to their countries of origin, 2) to bring the rest of their families to the receiving country, or 3) to lengthen their stay considerably. The number of refugees has also significantly increased since the mid-970s, as has the number of illegal migrants. After the mid-1970s, Europe began to experience integration problems. The different aspects of the impact of migration on social structures include 1) improvement of the housing situation for foreigners, 2) teaching migrants the language of the receiving country, 3) solving the unemployment problem of unskilled migrants, 4) improvement of educational and vocational qualifications of 2nd generation migrants, 5) development of programs to help unemployed wives of migrants to learn the language and meet indigenous women, 6) encouraging migrants to maintain their cultural identity and assisting them with reintegration if they return to their original country, 7) coping with the problems of refugees, and 8) solving the problems of illegal migration. Almost all receiving countries now severely restrict further immigration. [Those policies should result in

  15. Returns management in the supply chain

    OpenAIRE

    Anna Maria Jeszka

    2014-01-01

    Background:  The aim of this exploratory empirical research was to evaluate the level of cooperation in the area of reverse logistics between selected retail chains and logistics operators and suppliers; to identify and evaluate the influence the procedures of handling returns have on the relationships with customers, cost reduction, value recovery, inventory reduction and increasing profitability; as well as determining to what extent logistics operators are involved in the procedures o...

  16. Returns to Tenure: Time or Rank?

    DEFF Research Database (Denmark)

    Buhai, Ioan Sebastian

    -specific investment, efficiency-wages or adverse-selection models. However, rent extracting arguments as suggested by the theory of internal labor markets, indicate that the relative position of the worker in the seniority hierarchy of the firm, her 'seniority rank', may also explain part of the observed returns...... relative to their peer workers), as predicted by theories on unionized and insider-outsider markets....

  17. Probabilistic income-maximizing behavior in regional migration: an empirical test.

    Science.gov (United States)

    Weinstein, R I; Evans, R D

    1980-01-01

    "This paper provides an empirical test of the hypothesis that migrants consider income risk in their evaluation of the returns to migration in that higher levels of income risk for a given region reduce the rate of net migration into that region." Theoretical approaches to the incorporation of income risk in migration models are first considered, and alternative approaches are then tested using data on white and nonwhite net migration in the United States between 1960 and 1970. The results indicate support for the hypothesis that the extent of net migration is inversely affected by income risk. excerpt

  18. Return to the... past

    International Nuclear Information System (INIS)

    Ammerich, M.

    2009-01-01

    This article goes back over the incidents occurring during the summer 2008, that is to say the uranium release from the Socatri facility in the South of France. From this point, the purpose studies the radiological situation of the Camargue seashore; the levels of radioactivity are from 3 to thirty times higher than these ones expected in this area, but the natural radioactivity with thorium and uranium coming from the granitic massifs erosion brings an important part. It is difficult to make the part between human and natural contribution to ambient radioactivity. However, it appears that to limit the water consumption until the time of dilution played its part was absolutely necessary. Then, because it is question of water, the drinking water is tackled. Some mineral waters go over the recommended limits of doses. A last return to the past with the radioactive watches, but this time with actual watches that activate detection. Two watches contained promethium 147, 147 Pm is a beta emitter but also gamma emitter. To end, in Ireland and Great Britain, some fire detectors contain americium 241. In fact, this article constitutes a summary of different abnormalities around radioactivity. (N.C.)

  19. The return of religion

    Directory of Open Access Journals (Sweden)

    S. Griffioen

    2011-06-01

    Full Text Available Religion is back in Philosophy as a respectable subject. Part 1 first charts what MacIntyre, Taylor and Derrida have meant in this regard. Subsequently, it turns to the Enlightenment to determine what constituted the breakthrough. It is found that even where the Enlightenment gave maximum room to religion i.e. as a civic religion and as “religion of the heart” it still excluded a constitutive relation to a transcendent revelation. Part 2 centres on the religion-faith distinction in reformational philosophy. Similar to the Enlightenment, religion is understood as part of human nature. However, human nature itself is conceived as intrinsically religious and depending for its light on revelation. Secondly, “religion” in this context also encompasses idols and religious substitutes. Thus, it directs attention to shopping malls, football stadiums, health policy, et cetera, as possible contexts of a return of religion. Examples show that this has become a popular approach. However, most of the publications surveyed fail to distinguish between an “analogical” and a “pistically qualified” use of religion, and are open to exaggerations (the shopping mall and football stadiums as temples, etc.. At this junction, the relevance is shown of the religion-faith distinction as well as of Elaine Botha’s theory of metaphors. The epilogue offers an integration of parts one and two.

  20. PUC fast track nips returns

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In the first of what it says will be annual cost-of-capital proceedings to set returns on equity and rates of return on rate base for electric utilities, the California Public Utilities Commission (PUC) lowered from 1989 levels the 1990 returns on common equity (ROE) and rates of return (ROR) for the state's four major investor-owned electric utilities. Under this fast-track procedure, by May 8 of every year, utilities will have to file an application for rate adjustments that reflect their projected costs of capital for the following year

  1. The return to foreign aid

    DEFF Research Database (Denmark)

    Dalgaard, Carl-Johan Lars; Hansen, Henrik

    We investigate the marginal productivity of investment across countries. The aim is to estimate the return on investments financed by foreign aid and by domestic resource mobilization, using aggregate data. Both returns are expected to vary across countries and time. Consequently we develop...... a correlated random coefficients model, to estimate the average aggregate return on ‘aid investments’ and ‘domestic investments’. Across different estimators and two different sources for GDP and investment data our findings are remarkably robust; the average gross return on ‘aid investments’ is about 20 per...

  2. Geochemistry and radionuclide migration

    International Nuclear Information System (INIS)

    Isherwood, D.

    1978-01-01

    Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater

  3. Samtidskunst og migration

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    2010-01-01

    "Samtidskunst og migration. En oversigt over faglitteraturen" er en forskningsoversigt der gør status over hvad der hidtil er skrevet inden for det kunsthistoriske område om vor tids billedkunst og migration som politisk, socialt og kulturelt fænomen, primært i forbindelse med immigration til...

  4. The Great Migration.

    Science.gov (United States)

    Trotter, Joe William, Jr.

    2002-01-01

    Describes the migration of African Americans in the United States and the reasons why African Americans migrated from the south. Focuses on issues, such as the effect of World War I, the opportunities offered in the north, and the emergence of a black industrial working class. (CMK)

  5. Migrating Art History

    DEFF Research Database (Denmark)

    Ørum, Tania

    2012-01-01

    Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0.......Review of Hiroko Ikegami, The Great Migrator. Robert Rauschenberg and the Global Rise of American Art. Cambridge Mass., The MIT Press, 2010. 277 pages. ISBN 978-0-262-01425-0....

  6. College Student Migration.

    Science.gov (United States)

    Fenske, Robert H.; And Others

    This study examines the background characteristics of two large national samples of first-time enrolled freshmen who (a) attended college within their state of residence but away from their home community, (b) migrated to a college in an adjacent state, (c) migrated to a college in a distant state, and (d) attended college in their home community.…

  7. Migration, klima og sundhed

    DEFF Research Database (Denmark)

    Tellier, Siri; Carballo, Manuel

    2009-01-01

    Many tentative connections have been postulated between migration and climate. This article points to rural-urban migration, particularly into low elevation urban slums prone to flooding as an issue needing urgent attention by health professionals. It also notes the no-man's land in which environ...

  8. Migration in Burkina Faso

    NARCIS (Netherlands)

    Wouterse, F.S.

    2007-01-01

    Migration plays an important role in development and as a strategy for poverty reduction. A recent World Bank investigation finds a significant positive relationship between international migration and poverty reduction at the country level (Adams and Page 2003). Burkina Faso, whose conditions for

  9. Migration, Narration, Identity

    DEFF Research Database (Denmark)

    Leese, Peter

    (co-editor with Carly McLaughlin and Wladyslaw Witalisz) This book presents articles resulting from joint research on the representations of migration conducted in connection with the Erasmus Intensive Programme entitled «Migration and Narration» taught to groups of international students over...

  10. Reintegration of Pakistani return migrants from the Middle East in the domestic labour market.

    Science.gov (United States)

    Arif, G M

    1998-01-01

    This study compared the unemployment rates among return migrants and nonmigrants and examined the reintegration pattern of returnees in the domestic labor market. The study utilized three data sets: the 1980 World Bank Survey of Return Migrant Households; the 1986 ILO/ARTEP Survey of Return Migrant Households; the 1991 Pakistan Integrated Household Survey. Findings showed that unemployment rates were much higher among return migrants than nonmigrants. Although this difference narrowed with the passage of time, even among those who returned to Pakistan at least 18 months prior to the surveys, more than 10% of workers were unemployed. The multivariate analysis further showed that returnees, irrespective of the period elapsed since their return, were more likely to be unemployed than nonmigrants. With respect to the reintegration pattern of return migrants, the study revealed that variables indicating their human capital, such as occupation and pre-migration and during-migration work experience, appear to have a greater influence on their post-return adjustment than the variables related to economic positions such as savings. The results also showed that the types of jobs unemployed returnees were looking for differed substantially from those held by employed return migrants. A possibility was that unemployed returnees could not save enough from their overseas earnings to become self-employed. Thus, provision of credit for self-employment seems to be the right way to accommodate these workers.

  11. Relative deprivation and internal migration in the United States: A comparison of black and white men

    Science.gov (United States)

    Flippen, Chenoa

    2013-01-01

    While the link between geographic and social mobility has long been a cornerstone of sociological approaches to migration, recent research has cast doubt on the economic returns to internal U.S. migration. Moreover, important racial disparities in migration patterns remain poorly understood. Drawing on data from the 2000 census, I reappraise the link between migration and social mobility by taking relative deprivation into consideration. I examine the association between migration, disaggregated by region of origin and destination, and absolute and relative earnings and occupational prestige, separately by race. Findings lend new insight into the theoretical and stratification implications of growing racial disparities in migration patterns; while both blacks and whites who move north-south generally average lower absolute incomes than their stationary northern peers, they enjoy significantly higher relative social position. Moreover, the relative “gains” to migration are substantially larger for blacks than whites. The opposite patterns obtain for south-north migration. PMID:24391221

  12. The Globalisation of migration

    Directory of Open Access Journals (Sweden)

    Milan Mesić

    2002-04-01

    Full Text Available The paper demonstrates that contemporary international migration is a constitutive part of the globalisation process. After defining the concepts of globalisation and the globalisation of migration, the author discusses six key themes, linking globalisation and international migration (“global cities”, the scale of migration; diversification of migration flows; globalisation of science and education; international migration and citizenship; emigrant communities and new identities. First, in accordance with Saskia Sassen’s analysis, the author rejects the wide-spread notion that unqualified migrants have lost an (important role in »global cities«, i.e. in the centres of the new (global economy. Namely, the post-modern service sector cannot function without the support of a wide range of auxiliary unqualified workers. Second, a critical comparison with traditional overseas mass migration to the USA at the turn of the 19th and 20th centuries indicates that present international migration is, perhaps, less extensive – however it is important to take into consideration various limitations that previously did not exist, and thus the present migration potential is in really greater. Third, globalisation is more evident in a diversification of the forms of migration: the source area of migrants to the New World and Europe has expanded to include new regions in the world; new immigration areas have arisen (the Middle East, new industrial countries of the Far East, South Europe; intra-regional migration has intensified. Forth, globalisation is linked to an increased migration of experts and the pessimistic notion of a brain drain has been replaced by the optimistic idea of a brain gain. Fifth, contemporary international migration has been associated with a crisis of the national model of citizenship. Sixth, the interlinking of (migrant cultural communities regardless of distance and the physical proximity of cultural centres (the

  13. Seasonal migration determined by a trade-off between predator avoidance and growth

    DEFF Research Database (Denmark)

    Brönmark, C.; Skov, Christian; Brodersen, J.

    2008-01-01

    on commercially important fish species, such as salmon and trout. However, seasonal mass-migrations may occur also among other freshwater fish, e.g. in cyprinids that leave lakes and migrate into streams and wetlands in the fall and return back to the lake in spring. In a conceptual model, we hypothesized...

  14. Trophic impact of Atlantic bluefin tuna migrations in the North Sea

    DEFF Research Database (Denmark)

    Mariani, Patrizio; Andersen, Ken Haste; Lindegren, Martin

    2017-01-01

    and the stability of the fish community. The impact of a migrating top-predator is investigated here for Atlantic bluefin tuna in the North Sea. Bluefin tuna has been absent from the region for half-century, but recent years have seen recovery of migrations and a return of bluefin tuna in the area. We use a size...

  15. Local Villages and Global Networks: The Language and Migration Experiences of African Skilled Migrant Academics

    Science.gov (United States)

    Hurst, Ellen

    2017-01-01

    African skilled migrants and their circular and return migration strategies have received relatively little attention in the literature, with the previous focus of much African migration literature being on the net loss of skills to countries with developed economies in the global north. This article considers 13 interviews with African skilled…

  16. Migration Decision-Making among Mexican Youth: Individual, Family, and Community Influences

    Science.gov (United States)

    Tucker, Christine M.; Torres-Pereda, Pilar; Minnis, Alexandra M.; Bautista-Arredondo, Sergio A.

    2013-01-01

    We explored migration decisions using in-depth, semistructured interviews with male and female youth ages 14 to 24 (n = 47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were nonmigrants with relatives in the United States. Migrant and nonmigrant youth expressed different…

  17. Science 101: How Do Animals Navigate during Migration?

    Science.gov (United States)

    Robertson, William C.

    2007-01-01

    Migrating animals do amazing things. Homing pigeons can find their way "home" across hundreds of miles; salmon return to their spawning location thousands of miles away; turtles travel over eight thousand miles to lay their eggs in the spot where they originally hatched. Scientists have studied how animals navigate around the globe and have…

  18. Malaysia and forced migration

    Directory of Open Access Journals (Sweden)

    Arzura Idris

    2012-06-01

    Full Text Available This paper analyzes the phenomenon of “forced migration” in Malaysia. It examines the nature of forced migration, the challenges faced by Malaysia, the policy responses and their impact on the country and upon the forced migrants. It considers forced migration as an event hosting multifaceted issues related and relevant to forced migrants and suggests that Malaysia has been preoccupied with the issue of forced migration movements. This is largely seen in various responses invoked from Malaysia due to “south-south forced migration movements.” These responses are, however, inadequate in terms of commitment to the international refugee regime. While Malaysia did respond to economic and migration challenges, the paper asserts that such efforts are futile if she ignores issues critical to forced migrants.

  19. Nanoparticles migration in fractured rocks and affects on contaminant migration

    Science.gov (United States)

    Missana, Tiziana; Garcia-Gutierrez, Miguel; Alonso, Ursula

    2014-05-01

    In previous studies, the transport behavior of artificial (gold and latex) and natural (smectite clay) colloids, within a planar fracture in crystalline rock, was analyzed. In order to better understand the effects of colloid size, shape and surface charge on nanoparticle migration and especially on filtration processes on natural rock surfaces, different clay colloids and oxide nanoparticles were selected and their transport studied as a function of the residence time. In all the cases, (a fraction of) the nanoparticles travelled in the fracture as fast as or faster than water (with a retardation factor, Rf ≤ 1) and the observed Rf, was related to the Taylor dispersion coefficient, accounting for colloid size, water velocity and fracture width. However, under most of the cases, in contrast to the behavior of a conservative tracer, colloids recovery was much lower than 100 %. Differences in recovery between different nanoparticles, under similar residence times, were analyzed. In order to evaluate the possible consequences, on contaminant migration, of the presence of nanoparticles in the system, transport tests were carried out with both colloids and sorbing radionuclides. The overall capacity for colloids of enhancing radionuclide migration in crystalline rock fractures is discussed. Acknowledgments: The research leading to these results received funding from EU FP7/2007-2011 grant agreement Nº 295487 (BELBAR, Bentonite Erosion: effects on the Long term performance of the engineered Barrier and Radionuclide Transport) and by the Spanish Government under the project NANOBAG (CTM2011-2797).

  20. Modelling of migration and fate of selected persistent organic pollutants in the Gulf of Gdansk and the Vistula catchment (Poland): selected results from the EU ELOISE EuroCat project

    Science.gov (United States)

    Zukowska, Barbara; Pacyna, Jozef; Namiesnik, Jacek

    2005-02-01

    The ELOISE EU EuroCat project integrated natural and social sciences to link the impacts affecting the coastal sea to the human activities developed along the catchments. In EuroCat project river catchments' changes and their impact on the inflow area were analysed. The information was linked with environmental models. The part of the EU ELOISE EuroCat project focusing on the Vistula River catchment and the Baltic Sea costal zone was named VisCat. Within the framework of the EU ELOISE EuroCat - VisCat project, CoZMo-POP (Coastal Zone Model for Persistent Organic Pollutants), a non-steady-state multicompartmental mass balance model of long-term chemical fate in the coastal environment or the drainage basin of a large lake environment was used. The model is parameterised and tested herein to simulate the long-term fate and distribution of selected HCHs (hexachlorocyclohexanes) and PCBs (polychlorinated biphenyls) in the Gulf of Gdansk and the Vistula River drainage basin environment. The model can also be used in the future to predict future concentrations in relation to various emission scenarios and in management of economic development and regulations of substance-emission to this environment. However, this would require more extensive efforts in the future on model parameterisation and validation in order to increase the confidence in current model outputs.

  1. Returns on Investment in California County Departments of Public Health.

    Science.gov (United States)

    Brown, Timothy T

    2016-08-01

    To estimate the average return on investment for the overall activities of county departments of public health in California. I gathered the elements necessary to estimate the average return on investment for county departments of public health in California during the period 2001 to 2008-2009. These came from peer-reviewed journal articles published as part of a larger project to develop a method for determining return on investment for public health by using a health economics framework. I combined these elements by using the standard formula for computing return on investment, and performed a sensitivity analysis. Then I compared the return on investment for county departments of public health with the returns on investment generated for various aspects of medical care. The estimated return on investment from $1 invested in county departments of public health in California ranges from $67.07 to $88.21. The very large estimated return on investment for California county departments of public health relative to the return on investment for selected aspects of medical care suggests that public health is a wise investment.

  2. Returns on Investment in California County Departments of Public Health

    Science.gov (United States)

    2016-01-01

    Objectives. To estimate the average return on investment for the overall activities of county departments of public health in California. Methods. I gathered the elements necessary to estimate the average return on investment for county departments of public health in California during the period 2001 to 2008–2009. These came from peer-reviewed journal articles published as part of a larger project to develop a method for determining return on investment for public health by using a health economics framework. I combined these elements by using the standard formula for computing return on investment, and performed a sensitivity analysis. Then I compared the return on investment for county departments of public health with the returns on investment generated for various aspects of medical care. Results. The estimated return on investment from $1 invested in county departments of public health in California ranges from $67.07 to $88.21. Conclusions. The very large estimated return on investment for California county departments of public health relative to the return on investment for selected aspects of medical care suggests that public health is a wise investment. PMID:27310339

  3. Men’s Migration and Women’s Fertility in Rural Mozambique

    OpenAIRE

    Agadjanian, Victor; Yabiku, Scott T.; Cau, Boaventura

    2011-01-01

    Labor migration profoundly affects households throughout rural Africa. This study looks at how men’s labor migration influences marital fertility in a context where such migration has been massive while its economic returns are increasingly uncertain. Using data from a survey of married women in southern Mozambique, we start with an event-history analysis of birth rates among women married to migrants and those married to nonmigrants. The model detects a lower birth rate among migrants’ wives...

  4. Transnational nurse migration: future directions for medical anthropological research.

    Science.gov (United States)

    Prescott, Megan; Nichter, Mark

    2014-04-01

    Transnational nurse migration is a serious global health issue in which inequitably distributed shortages hinder health and development goals. This article selectively reviews the literature on nurse migration that has emerged from nursing, health planning, and the social sciences and offers productive directions for future anthropological research. The literature on global nurse migration has largely focused on push/pull economic logic and the concept of brain drain to understand the causes and effects of nurse migration. These concepts obscure political-economic, historical, and cultural factors that pattern nurse migration and influence the complex effects of nurse migration. Global nurse care chain analysis helps illuminate the numerous nodes in the production and migration of nurses, and management of this transnational process. Examples are provided from the Philippines and India to illustrate ways in which this analysis may be deepened, refined and rendered more critical by anthropological research. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. What drives 'soft deportation'? Understanding the rise in Assisted Voluntary Return among rejected asylum seekers in the Netherlands

    NARCIS (Netherlands)

    A.S. Leerkes (Arjen); van Os, R. (Rianne); Boersema, E. (Eline)

    2017-01-01

    textabstractStates experience difficulties in realizing the return of rejected asylum seekers, but migration control policies are becoming increasingly sophisticated. Against this background, we consider explanations for the increase in Assisted Voluntary Return from the Netherlands in the 2005-2011

  6. Returns management in the supply chain

    Directory of Open Access Journals (Sweden)

    Anna Maria Jeszka

    2014-09-01

    Full Text Available Background:  The aim of this exploratory empirical research was to evaluate the level of cooperation in the area of reverse logistics between selected retail chains and logistics operators and suppliers; to identify and evaluate the influence the procedures of handling returns have on the relationships with customers, cost reduction, value recovery, inventory reduction and increasing profitability; as well as determining to what extent logistics operators are involved in the procedures of handling returns in the analysed chains. Methods: Based on the literature and the experience of researchers from developed countries a questionnaire was constructed which was subsequently used to conduct empirical research in selected retail chains operating in two provinces in Poland. The questionnaire survey involved the sales personnel of selected retail chains in the clothing industry. Overall, 105 questionnaires were collected and analysed. Results: Various aspects of cooperation with suppliers and logistics operators in respect of handling returns were evaluated. Most indicators of cooperation were evaluated favourably, with the exception of joint access to the database, the use of inventory data available online, and access to information from the warehouse, which received low marks from the respondents. In the case of the studied stores, some of the activities in the area of reverse logistics are outsourced; for example, obtaining products from users, logistics, and the transport of returns are typically done by an outside operator. Inspection, sorting, appraisal, repairs, as well as the sales of refurbished products are usually performed within the studied retail corporations. Conclusions: The research has shown that the retail chains developed very good programmes for handling returns in the supply chain, as evidenced by the presented and highly rated indicators of cooperation, with the exception of information exchange where there is still much

  7. Corporate Governance and Equity Returns

    OpenAIRE

    Uchida, Shigeru

    2012-01-01

    This paper analyses the relationship between corporate governance and equity returns from the small investors view point. A primary survey has been conducted to gather the data required to examine the link. Preliminary result of the study shows that the four elements of governance: board structure, transparency, fairness and responsibility are positively related with equity returns.

  8. Between crisis, agency and return: the vulnerability of Bolivian migrants in Italy

    Directory of Open Access Journals (Sweden)

    Isabel Yépez del Castillo

    2014-09-01

    Full Text Available This article addresses the interrelationships between the economic crisis, international migration and the labour market, and their impact on female migration agency, both in the decision to migrate and in the subsequent possibility of return to Bolivia. Based on information collected in a large survey conducted in the city of Cochabamba and the tracing of multiple female migration trajectories, the extreme vulnerability of these women, who are the heads of single-parent households, working in elderly care in Bergamo, is shown. Despite their deteriorating working conditions in the context of current Italian economic crisis and the competition of immigrant care workers from countries of Eastern Europe, they choose to remain in Italy instead of returning to Bolivia.

  9. Migration and AIDS.

    Science.gov (United States)

    1998-01-01

    This article presents the perspectives of UNAIDS and the International Organization for Migration (IOM) on migration and HIV/AIDS. It identifies research and action priorities and policy issues, and describes the current situation in major regions of the world. Migration is a process. Movement is enhanced by air transport, rising international trade, deregulation of trade practices, and opening of borders. Movements are restricted by laws and statutes. Denial to freely circulate and obtain asylum is associated with vulnerability to HIV infections. A UNAIDS policy paper in 1997 and IOM policy guidelines in 1988 affirm that refugees and asylum seekers should not be targeted for special measures due to HIV/AIDS. There is an urgent need to provide primary health services for migrants, voluntary counseling and testing, and more favorable conditions. Research is needed on the role of migration in the spread of HIV, the extent of migration, availability of health services, and options for HIV prevention. Research must be action-oriented and focused on vulnerability to HIV and risk taking behavior. There is substantial mobility in West and Central Africa, economic migration in South Africa, and nonvoluntary migration in Angola. Sex workers in southeast Asia contribute to the spread. The breakup of the USSR led to population shifts. Migrants in Central America and Mexico move north to the US where HIV prevalence is higher.

  10. Asian student migration to Australia.

    Science.gov (United States)

    Shu, J; Hawthorne, L

    1996-01-01

    "This paper presents an overview of Asian student migration to Australia, together with an analysis of political and educational aspects of the overseas student programme. It focuses on some significant consequences of this flow for Australia. The characteristics of key student groups are contrasted to provide some perspective of the diversity of historical and cultural backgrounds, with the source countries of Malaysia, Indonesia and PRC [China] selected as case studies. Since the issue of PRC students in Australia has attracted considerable public attention and policy consideration, particular focus is placed on their experience." (SUMMARY IN FRE AND SPA) excerpt

  11. Analysis of primary cilia in directional cell migration in fibroblasts

    DEFF Research Database (Denmark)

    Christensen, Søren Tvorup; Veland, Iben; Schwab, Albrecht

    2013-01-01

    summarize selected methods in analyzing ciliary function in directional cell migration, including immunofluorescence microscopy, scratch assay, and chemotaxis assay by micropipette addition of PDGFRα ligands to cultures of fibroblasts. These methods should be useful not only in studying cell migration....... In particular, platelet-derived growth factor receptor alpha (PDGFRα) is compartmentalized to the primary cilium to activate signaling pathways that regulate reorganization of the cytoskeleton required for lamellipodium formation and directional migration in the presence of a specific ligand gradient. We...

  12. Labor migration in Asia.

    Science.gov (United States)

    Martin, P L

    1991-01-01

    "A recent conference sponsored by the United Nations Center for Regional Development (UNCRD) in Nagoya, Japan examined the growing importance of labor migration for four major Asian labor importers (Japan, Hong Kong, Malaysia, and Singapore) and five major labor exporters (Bangladesh, Korea, Pakistan, Philippines, and Thailand).... The conference concluded that international labor migration would increase within Asia because the tight labor markets and rising wages which have stimulated Japanese investment in other Asian nations, for example, have not been sufficient to eliminate migration push and pull forces...." excerpt

  13. A LIBS Boroscope for Evaluation of Mars Sample Return Core Candidates

    Data.gov (United States)

    National Aeronautics and Space Administration — The leading recommendation of the Decadal Survey [National Research Council, 2011] is &taking the first critical steps toward returning carefully selected...

  14. Returns to Schooling in Less Developed Countries: New Evidence from Zambia

    DEFF Research Database (Denmark)

    Nielsen, Helena Skyt; Westergård-Nielsen, Niels Chr.

    2001-01-01

    In our analysis of returns to schooling in Zambia, we look at the rural and urban population separately, and estimate the returns to schooling in each region based on a selection model in two stages. For urban areas we find that the returns to primary schooling are nil whereas the returns to scho...... to schooling beyond primary school are higher. For rural areas we find that the returns to primary schooling are positive and no different from the returns to education beyond primary school. Udgivelsesdato: JAN...

  15. Neuronal Migration Disorders

    Science.gov (United States)

    ... Understanding Sleep The Life and Death of a Neuron Genes At Work In The Brain Order Publications ... birth defects caused by the abnormal migration of neurons in the developing brain and nervous system. In ...

  16. Migration og etnicitet

    DEFF Research Database (Denmark)

    Christiansen, Connie Carøe

    2004-01-01

    Migration og etnicitet er aktuelle og forbundne fænomener, idet migration øger berøringsfladerne mellem befolkningsgrupper. Etniciteter formes i takt med at grænser drages imellem disse grupper. Imod moderniserings-teoriernes forventning forsvandt etnicitet ikke som en traditionel eller oprindelig...... måde at skabe tilhørsforhold på; globalt set fremstår vor tid istedet som en "migrationens tidsalder", der tilsyneladende også er en tidsalder, hvor kulturelle særtræk, i form af etnicitet, udgør vigtige linjer, hvorefter grupper skilller sig ud fra hinanden. Både migration og etnicitet bringer fokus...... den finder sted i modtagerlandet, men nyere perspektiver på migration, som begreber om medborgerskab, transnationalisme og diaspora er eksponenter for, søger udover den nationalstatslige ramme og inddrager konsekvenserne af migrationen for afsenderlande....

  17. New perspective on youth migration: Motives and family investment patterns

    Directory of Open Access Journals (Sweden)

    Jessica Heckert

    2015-10-01

    Full Text Available Background: Migration research commonly assumes that youth migrate as dependent family members or are motivated by current labor opportunities and immediate financial returns. These perspectives ignore how migration experiences, specifically motives and remittance behaviors, are unique to youth. Objective: This study investigates internal migration among the Haitian youth, aged 10-24. The study compares characteristics of youth who migrate with education and labor motives and determines characteristics associated with family financial support to youth migrants. Methods: The data are from the 2009 Haiti Youth Survey. Discrete-time event history analysis is used to model characteristics associated with education and labor migration. A two-stage Heckman probit model is used to determine characteristics associated with family financial support for two different samples of youth migrants. Results: Both education and labor migration become more common with increasing age. Education migration is more common among youth born outside the capital and those first enrolled in school on time. Labor migration differs little by region of birth, and is associated with late school enrollment. Moreover, rather than sending remittances home, many youth migrants continue to receive financial support from their parents. Provision of financial support to youth migrants is associated with current school enrollment. Female youth are more likely to be migrants, and less commonly receive support from their household of origin. Conclusions: Results illustrate that youth migration motives and remittance behaviors differ from those of adults, and many households of origin continue to invest in the human capital of youth migrants. Education migration may diversify household risk over an extended time horizon. Contribution: *

  18. Indonesia's migration transition.

    Science.gov (United States)

    Hugo, G

    1995-01-01

    This article describes population movements in Indonesia in the context of rapid and marked social and economic change. Foreign investment in Indonesia is increasing, and global mass media is available to many households. Agriculture is being commercialized, and structural shifts are occurring in the economy. Educational levels are increasing, and women's role and status are shifting. Population migration has increased over the decades, both short and long distance, permanent and temporary, legal and illegal, and migration to and between urban areas. This article focuses specifically on rural-to-urban migration and international migration. Population settlements are dense in the agriculturally rich inner areas of Java, Bali, and Madura. Although the rate of growth of the gross domestic product was 6.8% annually during 1969-94, the World Bank ranked Indonesia as a low-income economy in 1992 because of the large population size. Income per capita is US $670. Indonesia is becoming a large exporter of labor to the Middle East, particularly women. The predominance of women as overseas contract workers is changing women's role and status in the family and is controversial due to the cases of mistreatment. Malaysia's high economic growth rate of over 8% per year means an additional 1.3 million foreign workers and technicians are needed. During the 1980s urban growth increased at a very rapid rate. Urban growth tended to occur along corridors and major transportation routes around urban areas. It is posited that most of the urban growth is due to rural-to-urban migration. Data limitations prevent an exact determination of the extent of rural-to-urban migration. More women are estimated to be involved in movements to cities during the 1980s compared to the 1970s. Recruiters and middlemen have played an important role in rural-to-urban migration and international migration.

  19. People's Republic of China's Contemporary Migration Processes

    Directory of Open Access Journals (Sweden)

    Martina Bofulin

    2014-12-01

    Full Text Available The last three decades of significant political, economic and social transformations in the People’s Republic of China have had a profound impact on the Chinese society. The article addresses selected topics of Chinese migration that give a more nuanced understanding of migration processes and their contextualization within the contemporary Chinese society: the internal migration, emigration from China and international immigration to China. Migration from rural area towards urban eastern coast is one of the largest spatial movements in the human history, as well as a key component of the economic rise and subsequent social change. Emigration from China has, despite its relatively small volume, profoundly transformed local places of origin, a process that is not independent from the current international geopolitical situation. Immigration of international migrants to China is a relatively new phenomenon that puts the country on the map of migration destination countries for the first time in sixty years. The author concludes that the prevalent research perspectives on Chinese migration offer only a limited insight and suggests some possible alternative ways of analyzing this phenomenon.

  20. Fitness consequences of timing of migration and breeding in cormorants.

    Directory of Open Access Journals (Sweden)

    Phillip Gienapp

    Full Text Available In most bird species timing of breeding affects reproductive success whereby early breeding is favoured. In migratory species migration time, especially arrival at the breeding grounds, and breeding time are expected to be correlated. Consequently, migration time should also have fitness consequences. However, in contrast to breeding time, evidence for fitness consequences of migration time is much more limited. Climate change has been shown to negatively affect the synchrony between trophic levels thereby leading to directional selection on timing but again direct evidence in avian migration time is scarce. We here analysed fitness consequences of migration and breeding time in great cormorants and tested whether climate change has led to increased selection on timing using a long-term data set from a breeding colony on the island of Vorsø (Denmark. Reproductive success, measured as number of fledglings, correlated with breeding time and arrival time at the colony and declined during the season. This seasonal decline became steeper during the study period for both migration and breeding time and was positively correlated to winter/spring climate, i.e. selection was stronger after warmer winters/springs. However, the increasing selection pressure on timing seems to be unrelated to climate change as the climatic variables that were related to selection strength did not increase during the study period. There is indirect evidence that phenology or abundances of preferred prey species have changed which could have altered selection on timing of migration and breeding.

  1. Visualizing Human Migration Trhough Space and Time

    Science.gov (United States)

    Zambotti, G.; Guan, W.; Gest, J.

    2015-07-01

    Human migration has been an important activity in human societies since antiquity. Since 1890, approximately three percent of the world's population has lived outside of their country of origin. As globalization intensifies in the modern era, human migration persists even as governments seek to more stringently regulate flows. Understanding this phenomenon, its causes, processes and impacts often starts from measuring and visualizing its spatiotemporal patterns. This study builds a generic online platform for users to interactively visualize human migration through space and time. This entails quickly ingesting human migration data in plain text or tabular format; matching the records with pre-established geographic features such as administrative polygons; symbolizing the migration flow by circular arcs of varying color and weight based on the flow attributes; connecting the centroids of the origin and destination polygons; and allowing the user to select either an origin or a destination feature to display all flows in or out of that feature through time. The method was first developed using ArcGIS Server for world-wide cross-country migration, and later applied to visualizing domestic migration patterns within China between provinces, and between states in the United States, all through multiple years. The technical challenges of this study include simplifying the shapes of features to enhance user interaction, rendering performance and application scalability; enabling the temporal renderers to provide time-based rendering of features and the flow among them; and developing a responsive web design (RWD) application to provide an optimal viewing experience. The platform is available online for the public to use, and the methodology is easily adoptable to visualizing any flow, not only human migration but also the flow of goods, capital, disease, ideology, etc., between multiple origins and destinations across space and time.

  2. Migration, Business Formation, and the Informal Economy in Urban Mexico

    Science.gov (United States)

    Riosmena, Fernando

    2013-01-01

    Although the informal economy has grown rapidly in several developing nations, and migration and informality may be related to similar types of credit constraints and market failures, previous research has not systematically attempted to identify if migrant households are more likely to start informal and formal businesses alike and if this association varies across local contexts. We examine the relationship between prior U.S. migration and the creation of both formal and informal businesses in urban Mexico using several criteria to indirectly assess sector location. We use data from 56 communities from the Mexican Migration Project to estimate multilevel survival and nonmultilevel competing risk models predicting the likelihood of informal, formal, and no business formation. The recent return migration of the household head is strongly associated with informal business creation, particularly in economically dynamic areas. On the other hand, migrants are only marginally more likely to start formal businesses in highly economically dynamic sending areas. PMID:23721676

  3. Bereaved Employee: Returning to Work

    Science.gov (United States)

    ... Work Working Through Grief About Us The Bereaved Employee: Returning to Work By Helen Fitzgerald, CT After ... One employer called a grief therapist to help employees after a co-worker reported the death of ...

  4. Total anomalous pulmonary venous return

    Science.gov (United States)

    ... pulmonary venous return, x-ray References Fraser CD, Kane LC. Congenital heart disease. In: Townsend CM Jr, ... 62. Review Date 10/17/2017 Updated by: Michael A. Chen, MD, PhD, Associate Professor of Medicine, ...

  5. Capital Structure and Stock Returns

    OpenAIRE

    Ivo Welch

    2002-01-01

    U.S. corporations do not issue and repurchase debt and equity to counteract the mechanistic effects of stock returns on their debt-equity ratios. Thus over one- to five-year horizons, stock returns can explain about 40 percent of debt ratio dynamics. Although corporate net issuing activity is lively and although it can explain 60 percent of debt ratio dynamics (long-term debt issuing activity being most capital structurerelevant), corporate issuing motives remain largely a mystery. When stock...

  6. [Organising a successful return home].

    Science.gov (United States)

    Mézière, Anthony

    Discharge from hospital is a major component of the quality and efficiency of the healthcare system. The failures of the return home of elderly people testify to the difficulties of applying guidelines in the area of hospital discharge. The action plan decided in the hospital for a successful return home can be jeopardised for personal, relational, functional and structural reasons originating from the different players involved in the hospital discharge. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  7. Managing migration: the Brazilian case

    OpenAIRE

    Eduardo L. G. Rios-Neto

    2005-01-01

    The objective of this paper is to present the Brazilian migration experience and its relationship with migration management. The article is divided into three parts. First, it reviews some basic facts regarding Brazilian immigration and emigration processes. Second, it focuses on some policy and legal issues related to migration. Finally, it addresses five issues regarding migration management in Brazil.

  8. Migration and labour characteristics of slum dwellers in Bombay.

    Science.gov (United States)

    Desai, V

    1994-03-01

    This article presents a description of the migration and labor force characteristics of a sample of Bombay households in three slum areas. Interviews were conducted among 135 households in 1989. Slum areas were both similar and different from one another. Wadala slum had a large migrant population and a more integrated community structure. Slum dwellers tended to retain assets at their place of origin and were from agricultural areas in south Maharashtra. A greater proportion had close kin living in Wadala. Slum dwellers tended to be better-educated, formal-sector workers. Worli slum was less affluent and less close-knit. Migrants were mostly external migrants from Uttar and Andhra Pradesh. Kurla slum was the oldest slum area and had mixed traits. Kin interaction was voluntary and selective and flexible. The decision to return was unrelated to years spent in Bombay. Survey findings indicate that all areas had roughly equal proportions of internal and external migrants. Villagers migrated to cities due to unemployment in villages and the opportunity for social mobility and better employment. This analysis indicates that community-based politics were more influenced by state concerns than by the attributes of settlers or settlement types. State policies and market forces constrained poor people's housing options. The cost of urban housing and amenities rises as population density increases. The demand in urban areas for public services, housing, and infrastructure increases due to expanding populations, inadequate and deteriorating facilities, and social pressures. Governments are constrained by high debt levels and inadequate revenues. National agencies may be inefficient in the provision of services and infrastructure. There is growing pressure on international donors and developing country governments to reexamine the role of the private sector in financing and providing services and infrastructure.

  9. Management of the returning traveler with diarrhea.

    Science.gov (United States)

    de Saussure, Philippe P H

    2009-11-01

    Traveler's diarrhea (TD) strikes 20-60% of travelers visiting developing countries. It occurs shortly after the return and can be distinguished into two categories: acute and persistent TD. Acute TD, mostly caused by bacterial and viral pathogens, is usually mild and self-limited, and deserves empirical symptomatic and/or antibiotic therapy in selected cases. Fluoroquinolones are progressively superseded in this indication by azithromycin, a well tolerated macrolide active against most bacteria responsible for TD, including the quinolone-resistant species of Campylobacter jejuni that are now pervasive, especially in Southeast Asia and India. Persistent TD in the returning traveler is much rarer than its acute counterpart and may be associated with three types of causes. Persistent infections, among which Giardia and possibly Entamoeba predominate, account for a significant proportion of cases. Postinfectious processes represent a second cause and comprise temporary lactose malabsorption and postinfectious irritable bowel syndrome, now considered a major cause of persistent TD. Finally, apparently unrelated chronic diseases causing diarrhea are occasionally unmasked by TD and represent a third type of persistent TD, among which the well established case of incident inflammatory bowel disease poses intriguing pathogenesis questions. This review discusses recent advances in the field and provides practical recommendations for the management of TD in adult, immunocompetent returning travelers.

  10. A pilgrim's progress: Seeking meaning in primordial germ cell migration.

    Science.gov (United States)

    Cantú, Andrea V; Laird, Diana J

    2017-10-01

    Comparative studies of primordial germ cell (PGC) development across organisms in many phyla reveal surprising diversity in the route of migration, timing and underlying molecular mechanisms, suggesting that the process of migration itself is conserved. However, beyond the perfunctory transport of cellular precursors to their later arising home of the gonads, does PGC migration serve a function? Here we propose that the process of migration plays an additional role in quality control, by eliminating PGCs incapable of completing migration as well as through mechanisms that favor PGCs capable of responding appropriately to migration cues. Focusing on PGCs in mice, we explore evidence for a selective capacity of migration, considering the tandem regulation of proliferation and migration, cell-intrinsic and extrinsic control, the potential for tumors derived from failed PGC migrants, the potential mechanisms by which migratory PGCs vary in their cellular behaviors, and corresponding effects on development. We discuss the implications of a selective role of PGC migration for in vitro gametogenesis. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Climate Shocks and Migration: An Agent-Based Modeling Approach

    Science.gov (United States)

    Entwisle, Barbara; Williams, Nathalie E.; Verdery, Ashton M.; Rindfuss, Ronald R.; Walsh, Stephen J.; Malanson, George P.; Mucha, Peter J.; Frizzelle, Brian G.; McDaniel, Philip M.; Yao, Xiaozheng; Heumann, Benjamin W.; Prasartkul, Pramote; Sawangdee, Yothin; Jampaklay, Aree

    2016-01-01

    This is a study of migration responses to climate shocks. We construct an agent-based model that incorporates dynamic linkages between demographic behaviors, such as migration, marriage, and births, and agriculture and land use, which depend on rainfall patterns. The rules and parameterization of our model are empirically derived from qualitative and quantitative analyses of a well-studied demographic field site, Nang Rong district, Northeast Thailand. With this model, we simulate patterns of migration under four weather regimes in a rice economy: 1) a reference, ‘normal’ scenario; 2) seven years of unusually wet weather; 3) seven years of unusually dry weather; and 4) seven years of extremely variable weather. Results show relatively small impacts on migration. Experiments with the model show that existing high migration rates and strong selection factors, which are unaffected by climate change, are likely responsible for the weak migration response. PMID:27594725

  12. Prestack depth migration

    International Nuclear Information System (INIS)

    Postma, R.W.

    1991-01-01

    Two lines form the southern North Sea, with known velocity inhomogeneities in the overburden, have been pre-stack depth migrated. The pre-stack depth migrations are compared with conventional processing, one with severe distortions and one with subtle distortions on the conventionally processed sections. The line with subtle distortions is also compared with post-stack depth migration. The results on both lines were very successful. Both have already influenced drilling decisions, and have caused a modification of structural interpretation in the respective areas. Wells have been drilled on each of the lines, and well tops confirm the results. In fact, conventional processing led to incorrect locations for the wells, both of which were dry holes. The depth migrated sections indicate the incorrect placement, and on one line reveals a much better drilling location. This paper reports that even though processing costs are high for pre-stack depth migration, appropriate use can save millions of dollars in dry-hole expense

  13. Migration = cloning; aliasiing

    DEFF Research Database (Denmark)

    Hüttel, Hans; Kleist, Josva; Nestmann, Uwe

    1999-01-01

    In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object’s state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider the creat......In Obliq, a lexically scoped, distributed, object-oriented programming language, object migration was suggested as the creation of a copy of an object’s state at the target site, followed by turning the object itself into an alias, also called surrogate, for the remote copy. We consider...... the creation of object surrogates as an abstraction of the abovementioned style of migration. We introduce Øjeblik, a distribution-free subset of Obliq, and provide three different configuration-style semantics, which only differ in the respective aliasing model. We show that two of the semantics, one of which...... matches Obliq’s implementation, render migration unsafe, while our new proposal for a third semantics is provably safe. Our work suggests a straightforward repair of Obliq’s aliasing model such that it allows programs to safely migrate objects....

  14. The return of international labour migrants in the ESCAP Region.

    Science.gov (United States)

    1986-03-01

    The social phenomenon of massive temporary international labor migration from the ESCAP region has emerged extremely rapidly. Within 10 years, the number of persons from ESCAP countries grew from a negligible one to 3.5 million. Related research and government policies have lagged behind this latest surge in migration. Most research conducted has been small-scale and lacks an analytical or theoretical framework. Policy formulation for temporary labor migration is difficult because most of the rapid growth in the industry has occurred as a result of private efforts, with a minimum of government intervention. It is now difficult, for the government to provide effective regulations or measures to stimulate and assist the process. Regulations on compulsory remittances or overseas minimum wages have proved to be unrealistic and, if not rescinded, are routinely circumvented. The most effective policies to assist return migrants may not be those which are intended to do so, but those which control the earlier stages of the migration process, such as recruitment, working conditions, and banking arrangements. The most valuable policies may also include those affecting education, training, employment, and general socioeconomic growth. Governments are recommended to provide social services for migrants and their families who are experiencing problems, and to institute community programs in areas with a large number of labor migrants. Governmental efforts to promote forms of labor migration beneficial to the workers would be valuable and should include measures to identify overseas labor markets for employing its nationals, government ot government labor contracts, and government participation in joint-venture projects. International migration should be analyzed in the context of theories and social change in order for governments to formulate effective measures for the reintegration of returning workers. Labor migration on the current scale has many social implications for

  15. Virtual machine migration in an over-committed cloud

    KAUST Repository

    Zhang, Xiangliang

    2012-04-01

    While early emphasis of Infrastructure as a Service (IaaS) clouds was on providing resource elasticity to end users, providers are increasingly interested in over-committing their resources to maximize the utilization and returns of their capital investments. In principle, over-committing resources hedges that users - on average - only need a small portion of their leased resources. When such hedge fails (i.e., resource demand far exceeds available physical capacity), providers must mitigate this provider-induced overload, typically by migrating virtual machines (VMs) to underutilized physical machines. Recent works on VM placement and migration assume the availability of target physical machines [1], [2]. However, in an over-committed cloud data center, this is not the case. VM migration can even trigger cascading overloads if performed haphazardly. In this paper, we design a new VM migration algorithm (called Scattered) that minimizes VM migrations in over-committed data centers. Compared to a traditional implementation, our algorithm can balance host utilization across all time epochs. Using real-world data traces from an enterprise cloud, we show that our migration algorithm reduces the risk of overload, minimizes the number of needed migrations, and has minimal impact on communication cost between VMs. © 2012 IEEE.

  16. Human Capital Theory and Internal Migration: Do Average Outcomes Distort Our View of Migrant Motives?

    Science.gov (United States)

    Korpi, Martin; Clark, William A W

    2017-05-01

    By modelling the distribution of percentage income gains for movers in Sweden, using multinomial logistic regression, this paper shows that those receiving large pecuniary returns from migration are primarily those moving to the larger metropolitan areas and those with higher education, and that there is much more variability in income gains than what is often assumed in models of average gains to migration. This suggests that human capital models of internal migration often overemphasize the job and income motive for moving, and fail to explore where and when human capital motivated migration occurs.

  17. DISCERNING EXOPLANET MIGRATION MODELS USING SPIN-ORBIT MEASUREMENTS

    International Nuclear Information System (INIS)

    Morton, Timothy D.; Johnson, John Asher

    2011-01-01

    We investigate the current sample of exoplanet spin-orbit measurements to determine whether a dominant planet migration channel can be identified, and at what confidence. We use the predictions of Kozai migration plus tidal friction and planet-planet scattering as our misalignment models, and we allow for a fraction of intrinsically aligned systems, explainable by disk migration. Bayesian model comparison demonstrates that the current sample of 32 spin-orbit measurements strongly favors a two-mode migration scenario combining planet-planet scattering and disk migration over a single-mode Kozai migration scenario. Our analysis indicates that between 34% and 76% of close-in planets (95% confidence) migrated via planet-planet scattering. Separately analyzing the subsample of 12 stars with T eff >6250 K-which Winn et al. predict to be the only type of stars to maintain their primordial misalignments-we find that the data favor a single-mode scattering model over Kozai with 85% confidence. We also assess the number of additional hot star spin-orbit measurements that will likely be necessary to provide a more confident model selection, finding that an additional 20-30 measurement has a >50% chance of resulting in a 95% confident model selection, if the current model selection is correct. While we test only the predictions of particular Kozai and scattering migration models in this work, our methods may be used to test the predictions of any other spin-orbit misaligning mechanism.

  18. The "third option": Oscilliatory migrations of retired guest workers

    Directory of Open Access Journals (Sweden)

    Antonijević Dragana

    2016-01-01

    Full Text Available The subject of this study is focused on new migration tendencies of retired guest workers. This paper represents one part of a study conducted during 2014 in eastern Serbia and Vienna regarding life strategies of retired labor migrants. In domestic (Serbian social sciences this subject was neglected, but recently it has attracted global social scientific attention with an idea of interdisciplinary merge of migration and age studies. To the day, global literature has only covered retired migrant laborers return to their home countries, but recent studies show changes in migration tendencies of retired laborers of many different nationalities, who have spent their work age in Western Europe. These new migration patterns were called “oscillatory movement” or as a new, alternative “third option”. They are only a form of seasonal and circular migrations which present the most dominant fashion of modern migrant mobility in Europe. Therefore we wanted to see what is the situation with labor migrants from Serbia – do they return to Serbia once they retire or not, and what are their reasons for choosing to live on “two addresses”. [Projekat Ministarstva nauke Republike Srbije, br. 177035: Antropološko proučavanje Srbije – od kulturnog nasleđa do modernog društva

  19. En fornemmelse for migration

    DEFF Research Database (Denmark)

    Schütze, Laura Maria

    Afhandlingen undersøger, hvordan sted, museets rolle som aktør og religion er relevante for produktionen af migration på Immigrantmuseet (2012) og i Københavns Museums udstilling At blive københavner (2010). Afhandlingen er baseret på udstillingsanalyse samt interview med relevant museumsfagligt......, anvendes som virkemidler til at nuancere migration og distancere udstillingen fra den offentlige debat om indvandring. Afhandlingen peger på, at produktionen af den nyere danske historie på museum er præget af et fravær af religion. Det skyldes, at de museumsfaglige praksisser og traditioner afspejler en...... identiteter, som vi tager for givet: nationer, byer, kvinder - såvel som migration og religion. Afhandlingen argumenterer følgelig for, at museernes produktion af (materiel) religion er et særdeles relevant, men kun ringe udforsket, genstandsfelt for religionssociologien....

  20. O IMPACTO DA MIGRAÇÃO DAS EMPRESAS PARA OS NÍVEIS DIFERENCIADOS DE GOVERNANÇA CORPORATIVA DA BM&F BOVESPA SOBRE O RISCO E O RETORNO DE SUAS AÇÕES./THE IMPACT OF THE MIGRATION OF BUSINESSES TO THE DIFFERENTIATED LEVELS OF BM&F BOVESPA’S CORPORATE GOVERNANCE OVER THE AND RETURN OF ITS SHARES.

    Directory of Open Access Journals (Sweden)

    Ricardo Luiz Menezes da Silva

    2012-08-01

    Full Text Available A transparência das informações é importante para se ter uma diminuição na assimetria das mesmas. Quanto mais informações de qualidade há sobre o negócio ou desempenho econômico e financeiro de determinada empresa, teoricamente, mais se pode esperar uma diferente percepção do risco por parte do investidor. O objetivo deste estudo foi verificar se a iniciativa das empresas em aderir aos Níveis Diferenciados de Governança Corporativa da BM&F BOVESPA impacta tanto no risco quanto no retorno dos preços de fechamento de suas ações. Para isso, foram utilizados os retornos diários de 252 dias antes e após a adesão das empresas aos NDGC. Foram feitos os testes de Kolmogorov-Smirnov para análise da normalidade, o teste paramétrico de médias emparelhadas e o teste não paramétrico de Wilcoxon para medidas de risco absoluto (desvio-padrão e relativo (beta, além de retorno. Foram analisados os comportamentos dos papéis de 48 empresas. Os resultados mostraram que as médias dos retornos das açõesempresariais não apresentaram diferenças significativas antes e após a data de adesão aos NDGC. Por outro lado, as proxies de risco apresentaram-se significativamente diferentes./ The transparency of information is important to diminish the asymmetry of information. Themore quality information there is about the business, or financial and economic performance of a certain company, theoretically, the more one can expect a different perception of risk by the investor. The aim of this study was to verify whether the initiative of the companies to adhere to BM&F BOVESPA’s Differentiated Levels of Corporate Governance impacts both at risk and return of the closing price of its shares. For that, daily returns of 252 days before and after the accession of companies to NDGC were used. Over the measures of absolute risk (standard deviation and relative risk (beta, and return, Kolmogorov-Smirnov tests were made in order to analyze normality

  1. Sealed Planetary Return Canister (SPRC), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Sample return missions have primary importance in future planetary missions. A basic requirement is that samples be returned in pristine, uncontaminated condition,...

  2. What's driving migration?

    Science.gov (United States)

    Kane, H

    1995-01-01

    During the 1990s investment in prevention of international or internal migration declined, and crisis intervention increased. The budgets of the UN High Commissioner for Refugees and the UN Development Program remained about the same. The operating assumption is that war, persecution, famine, and environmental and social disintegration are inevitable. Future efforts should be directed to stabilizing populations through investment in sanitation, public health, preventive medicine, land tenure, environmental protection, and literacy. Forces pushing migration are likely to increase in the future. Forces include depletion of natural resources, income disparities, population pressure, and political disruption. The causes of migration are not constant. In the past, migration occurred during conquests, settlement, intermarriage, or religious conversion and was a collective movement. Current migration involves mass movement of individuals and the struggle to survive. There is new pressure to leave poor squatter settlements and the scarcities in land, water, and food. The slave trade between the 1500s and the 1800s linked continents, and only 2-3 million voluntarily crossed national borders. Involuntary migration began in the early 1800s when European feudal systems were in a decline, and people sought freedom. Official refugees, who satisfy the strict 1951 UN definition, increased from 15 million in 1980 to 23 million in 1990 but remained a small proportion of international migrants. Much of the mass movement occurs between developing countries. Migration to developed countries is accompanied by growing intolerance, which is misinformed. China practices a form of "population transfer" in Tibet in order to dilute Tibetan nationalism. Colonization of countries is a new less expensive form of control over territory. Eviction of minorities is another popular strategy in Iraq. Public works projects supported by foreign aid displace millions annually. War and civil conflicts

  3. Unix Application Migration Guide

    CERN Document Server

    Microsoft. Redmond

    2003-01-01

    Drawing on the experience of Microsoft consultants working in the field, as well as external organizations that have migrated from UNIX to Microsoft® Windows®, this guide offers practical, prescriptive guidance on the issues you are likely to face when porting existing UNIX applications to the Windows operating system environment. Senior IT decision makers, network managers, and operations managers will get real-world guidance and best practices on planning and implementation issues to understand the different methods through which migration or co-existence can be accomplished. Also detailing

  4. Migrating for a Profession

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2015-01-01

    a strong sense of agency and self-empowerment. In the post-WWII period, numerous Caribbean women trained in nursing at British hospitals that have been described as marred by race and gender related inequality and associated forms of exploitation. Yet, the nurses interviewed about this training emphasised......Youths from the Global South migrating for further education often face various forms of discrimination. This Caribbean case study discusses how conditions in the home country can provide a foundation for educational migration that helps the migrants overcome such obstacles and even develop...... in which it enabled these Caribbean women to stake out a new life for themselves....

  5. On the record: you can go home again: Mexican migrants return in record numbers

    OpenAIRE

    Weiss, Michael

    2013-01-01

    Agustín Escobar Latapí is a research professor at the Center for Research and Higher Learning in Social Anthropology in Guadalajara, Mexico, and is a member of Mexico’s National Academy of Sciences. A specialist in Mexican social policy and migration, he discusses the southward return of migrants and its implications.

  6. Abnormal Returns and Contrarian Strategies

    Directory of Open Access Journals (Sweden)

    Ivana Dall'Agnol

    2003-12-01

    Full Text Available We test the hypothesis that strategies which are long on portfolios of looser stocks and short on portfolios of winner stocks generate abnormal returns in Brazil. This type of evidence for the US stock market was interpreted by The Bondt and Thaler (1985 as reflecting systematic evaluation mistakes caused by investors overreaction to news related to the firm performance. We found evidence of contrarian strategies profitability for horizons from 3 months to 3 years in a sample of stock returns from BOVESPA and SOMA from 1986 to 2000. The strategies are more profitable for shorter horizons. Therefore, there was no trace of the momentum effect found by Jagadeesh and Titman (1993 for the same horizons with US data. There are remaing unexplained positive returns for contrarian strategies after accounting for risk, size, and liquidity. We also found that the strategy profitability is reduced after the Real Plan, which suggests that the Brazilian stock market became more efficient after inflation stabilization.

  7. Determinants of International Migration: The Nigerian Experience

    Directory of Open Access Journals (Sweden)

    Samuel Antwi Darkwah

    2014-01-01

    Full Text Available This paper examines some determinants of international migration in Nigeria using annual time series data spanning the period 1991–2011. Using ordinary least square regression method, the results indicate that the level of unemployment, migrants’ remittances and population growth are the key determinants of emigration from Nigeria to other countries, statistically significant at 0.01 level.In a country where unemployment rate is very high, this movement is likely to help in reducing pressures on the labour market. Migrants’ remittances might also help in alleviating poverty within households. Migrants’ remittance to Nigeria has surpassed both Foreign Direct Investment and Net Official Development Assistance inflows, making it one amongst the major sources of foreign earnings to Nigeria. Nigerians will continue to migrate to other parts of the world so long as the reasons or causes for their movement are not fully addressed i.e. if political and socioeconomic issues in the country do not improve. The Nigerian government should as a matter of urgency, create better jobs and conducive environment in order to stop people from migrating while at the same time encouraging its skilled labour abroad to return home to help in national development.

  8. Dynamic returns of beta arbitrage

    OpenAIRE

    Nascimento, Mafalda

    2017-01-01

    This thesis studies the patterns of the abnormal returns of the beta strategy. The topic can be helpful for professional investors, who intend to achieve a better performance in their portfolios. Following the methodology of Lou, Polk, & Huang (2016), the COBAR measure is computed in order to determine the levels of beta arbitrage in the market in each point in time. It is argued that beta arbitrage activity can have impact on the returns of the beta strategy. In fact, it is demonstrated that...

  9. Sovereign Risk and Currently Returns

    DEFF Research Database (Denmark)

    Della Corte, Pasquale; Sarno, Lucio; Schmeling, Maik

    We empirically investigate the relation between sovereign risk and exchange rates for a broad set of currencies. An increase in the credit default swap (CDS) spread of a country is accompanied by a significant depreciation of the exchange rate. More generally, CDS spread changes have substantial...... explanatory power for currency returns which is largely driven by shocks to global credit risk. Consistent with the notion that sovereign risk is priced, we find that a country's exposure to global credit risk forecasts excess returns to trading exchange rates as well as to trading on the volatility, skewness...

  10. Sovereign Risk and Currency Returns

    DEFF Research Database (Denmark)

    Della Corte, Pasquale; Sarno, Lucio; Schmeling, Maik

    We empirically investigate the relation between sovereign risk and exchange rates for a broad set of currencies. An increase in the credit default swap (CDS) spread of a country is accompanied by a significant depreciation of the exchange rate. More generally, CDS spread changes have substantial...... explanatory power for currency returns which is largely driven by shocks to global credit risk. Consistent with the notion that sovereign risk is priced, we find that a country's exposure to global credit risk forecasts excess returns to trading exchange rates as well as to trading on the volatility, skewness...

  11. Education as a means of smooth rural‐urban migration: some ...

    African Journals Online (AJOL)

    This paper models the impact of education on rural‐urban migration in selected villages of Ethiopia. Level of education is found to be significant in triggering ruralurban migration even after accounting for its indirect effect on migration through earnings differential. This may support the argument that education changes the ...

  12. Understanding soaring bird migration through interactions and decisions at the individual level

    NARCIS (Netherlands)

    van Loon, E.E.; Shamoun-Baranes, J.; Bouten, W.; Davis, S.L.

    2011-01-01

    Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel

  13. The conditional returns to origin-country human capital among Turkish and Moroccan immigrants in Belgium.

    Science.gov (United States)

    Kanas, Agnieszka; van Tubergen, Frank

    2014-07-01

    This study extends the analysis of the economic returns to pre-migration human capital by examining the role of the receiving context, co-ethnic residential concentration, and post-migration investments in human capital. It uses large-scale survey data on Turkish and Moroccan immigrants in Belgium. The analysis demonstrates that regarding employment, Moroccan immigrants, that is, those originating from former French colonies receive larger returns to their origin-country education and work experience in French- vs. Dutch-speaking regions. Other than the positive interaction effect between co-ethnic residential concentration and work experience on employment, there is little evidence that co-ethnic concentration increases the returns to origin-country human capital. Speaking the host-country language facilitates economic returns to origin-country work experience. Conversely, immigrants who acquire host-country credentials and work experience receive lower returns to origin-country education and experience, suggesting that, at least among low-skilled immigrants, pre- and post-migration human capital substitute rather than complement each other. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Migration from a terrestrial network to a satellite network - Risks/constraints/payoffs

    Science.gov (United States)

    Homon, K. A.

    The migration method is regarded as a straightforward approach to a customer's requirements while addressing the known constraints. The migration plan organizes, controls, and communicates the extensive number of tasks, schedules, technical details, and node-by-node conversion details using the selected migration method as its cornerstone. It is noted that a successful migration plan must also provide the flexibility and robustness necessary to handle the unforeseen changes that will occur over the three- to four-year migration period. A baseline network provides a solid structural underpinning for the migration plan.

  15. Climate Change, Agriculture and Migration: A Survey

    Directory of Open Access Journals (Sweden)

    Chiara Falco

    2018-05-01

    Full Text Available This paper proposes a selective review of the classical economics-based literature on climate change and migration, focusing on the extent to which agriculture might be considered a key mediating channel linking climate change to migration. Overall, climate change is expected to have large and negative effects on the global economy. These effects are even more evident whenever the economic sector considered is the agricultural one, particularly in developing countries. Hence, migration can be viewed as a specific form of adaptation implemented by individuals and households, enabling them to cope, among other things, with weather-induced risk. We show that the importance of agriculture emerges from both plenty of micro-level country studies and relatively few macro-level analyses using cross-sectional data over longer time periods. Thus, policy actions targeted to sustainable agriculture and rural development can both help tackle the challenges posed by climate change and create opportunities in the face of growing migration issues. However, we also stress that much of the current evidence is based on statistical associations that have nothing to do with causal inferences. This calls for the use of a more structural approach and more sophisticated research designs, enabling the researchers to better discriminate among different mechanisms concurrently at work. In addition, further research should be addressed to the role played by food security, a complex dimension largely missing in the current debates on climate change and migration.

  16. Migrating the Light

    DEFF Research Database (Denmark)

    Sørensen, Bent

    The migration of Blaga’s universalist, even centralist poems from Romanian of the first third of the 20th C. into American of the first fifth of the 21st C. illustrates the uses of Pierre Joris’s nomadic methods. My translations of Blaga read well for a teenage audience whose only exposure to lit...

  17. Describing migration spatial structure

    NARCIS (Netherlands)

    Rogers, A; Willekens, F; Little, J; Raymer, J

    The age structure of a population is a fundamental concept in demography and is generally depicted in the form of an age pyramid. The spatial structure of an interregional system of origin-destination-specific migration streams is, however, a notion lacking a widely accepted definition. We offer a

  18. Brain Migration Revisited

    Science.gov (United States)

    Vinokur, Annie

    2006-01-01

    The "brain drain/brain gain" debate has been going on for the past 40 years, with irresolvable theoretical disputes and unenforceable policy recommendations that economists commonly ascribe to the lack of reliable empirical data. The recent report of the World Bank, "International migration, remittances and the brain drain", documents the…

  19. Migration and Africa

    DEFF Research Database (Denmark)

    Zoppi, Marco

    2014-01-01

    European powers imposed the nation-state on Africa through colonialism. But even after African independencies, mainstream discourses and government policies have amplified the idea that sedentariness and the state are the only acceptable mode of modernity. Migration is portrayed as a menace...

  20. Migration as Adventure

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2018-01-01

    Narratives of adventure constitute a well-established convention of describing travel experiences, yet the significance of this narrative genre in individuals’ accounts of their migration and life abroad has been little investigated. Drawing on Simmel and Bakhtin, among others, this article...

  1. Digitizing migration heritage

    DEFF Research Database (Denmark)

    Marselis, Randi

    2011-01-01

    Museums are increasingly digitizing their collections and making them available to the public on-line. Creating such digital resources may become means for social inclusion. For museums that acknowledge migration history and cultures of ethnic minority groups as important subjects in multiethnic...

  2. The politicisation of migration

    NARCIS (Netherlands)

    van der Brug, W.; D' Amato, G.; Berkhout, J.; Ruedin, D.

    2015-01-01

    Why are migration policies sometimes heavily contested and high on the political agenda? And why do they, at other moments and in other countries, hardly lead to much public debate? The entrance and settlement of migrants in Western Europe has prompted various political reactions. In some countries

  3. Practical Data Migration

    CERN Document Server

    Morris, Johny

    2012-01-01

    This book is for executives and practitioners tasked with the movement of data from old systems to a new repository. It uses a series of steps guaranteed to get the reader from an empty new system to one that is working and backed by the user population. Using this proven methodology will vastly increase the chances of a successful migration.

  4. Migration pathways in soils

    International Nuclear Information System (INIS)

    Gronow, J.R.

    1986-01-01

    This study looked at diffusive migration through three types of deformation; the projectile pathways, hydraulic fractures of the sediments and faults, and was divided into three experimental areas: autoradiography, the determination of diffusion coefficients and electron microscopy of model projectile pathways in clay. For the autoradiography, unstressed samples were exposed to two separate isotopes, Pm-147 (a possible model for Am behaviour) and the poorly sorbed iodide-125. The results indicated that there was no enhanced migration through deformed kaolin samples nor through fractured Great Meteor East (GME) sediment, although some was evident through the projectile pathways in GME and possibly through the GME sheared samples. The scanning electron microscopy of projectile pathways in clay showed that emplacement of a projectile appeared to have no effect on the orientation of particles at distances greater than two projectile radii from the centre of a projectile pathway. It showed that the particles were not simply aligned with the direction of motion of the projectile but that, the closer to the surface of a particular pathway, the closer the particles lay to their original orientation. This finding was of interest from two points of view: i) the ease of migration of a pollutant along the pathway, and ii) possible mechanisms of hole closure. It was concluded that, provided that there is no advective migration, the transport of radionuclides through sediments containing these defects would not be significantly more rapid than in undeformed sediments. (author)

  5. India: 'brain drain' or the migration of talent?

    Science.gov (United States)

    Oommen, T K

    1989-09-01

    2 views on "brain drain" exist: 1) LDCs lose their enormous investments on higher education when skilled people migrate to other countries and 2) LDCs are exaggerating the problem and only a few skilled people migrate at 1 time. India does not completely lose its investment in education when professionals migrate, since the migrants still contribute to knowledge and also send remittances to relatives in India. Unemployed educated people would cause a greater drain on India's resources than educated migrants. The author prefers the phrase migration of talent to brain drain, since the former indicates a 2-way movement. Most migrants from LDCs are students. About 11,000 university graduates leave India every year for advanced study and/or work. A conservative estimate is that 2500 will remain abroad permanently. Most professionals who migrate go to the US and Canada. Factors promoting migration include 1) unemployment, 2) immigration rules, 3) colonial links, 4) financial incentives and material benefits, 5) pursuit of higher education, 6) improvement of working conditions and facilities, 7) avoidance of excessive bureaucratic procedures, and 8) compensation for the mismatch between Indian education and employment. Reasons for returning to India include 1) deference to wives who were unable to adjust to a foreign way of life, 2) contributing to Indian development, and 3) racial discrimination. It will probably not be possible to lure back migrants who left for material reasons. Attractive job offers could entice back those who left for advanced training. To encourage the return of those who left to pursue high quality research, India must 1) increase expenditure on research and development, possibly through the private industrial sector, 2) promote travel to other countries for professional enrichment, and 3) improve conditions of research work. The article concludes with an analysis of migration of talent from 3 perspectives: 1) the individual, 2) the nation

  6. The Impact of International Teacher Migration on Schooling in Developing Countries--The Case of Southern Africa

    Science.gov (United States)

    Appleton, Simon; Sives, Amanda; Morgan, W. John

    2006-01-01

    Whilst the migration of teachers has been a phenomenon for hundreds of years, the advent of "globalisation" has seen such migration return to prominence. This article focuses on the experiences of two developing countries in Southern Africa which have been on different ends of the process: South Africa as a net sender of teachers and…

  7. Spontaneous correction of pathologic tooth migration and reduced infrabony pockets following nonsurgical periodontal therapy: a case report.

    Science.gov (United States)

    Sato, Shuichi; Ujiie, Hisashi; Ito, Koichi

    2004-10-01

    This case report describes the spontaneous correction of pathologic tooth migration and reduced infrabony pockets after nonsurgical periodontal therapy. A 3-mm diastema between the maxillary incisors was closed completely, and the mandibular teeth, which had migrated pathologically, returned to the optimal position. Clinical evaluation showed a significant reduction in probing depth, with increased clinical attachment and bone deposition demonstrated radiologically.

  8. Migration Studies and Academic Research on International Migration Policies in Argentina

    Directory of Open Access Journals (Sweden)

    Eduardo Domenech

    2017-05-01

    Full Text Available This article approaches the historical development of the field of migratory studies in Argentina and makes a review of the academic production around the so - called "migratory policies." The systematization of these studies, historically placed on migration policies, aims to highlight some of the most significant contributions of the research during the last 30 years, to understand or explain various aspects and dimensions of the Argentinean migration policy. To achieve this, texts were selected that derived from empirical research that explicitly assume the migratory policies as the object of study, or whose themes and research problems adopt as a framework for discussion the policies and practices aimed at regulating migration and mobility in Argentina. The organization and presentation of these selected texts consider issues related to the interests and thematic concerns, disciplinary and analytical approaches, distinct periods, scales of analysis and sources of information.

  9. Multisource Least-squares Reverse Time Migration

    KAUST Repository

    Dai, Wei

    2012-12-01

    Least-squares migration has been shown to be able to produce high quality migration images, but its computational cost is considered to be too high for practical imaging. In this dissertation, a multisource least-squares reverse time migration algorithm (LSRTM) is proposed to increase by up to 10 times the computational efficiency by utilizing the blended sources processing technique. There are three main chapters in this dissertation. In Chapter 2, the multisource LSRTM algorithm is implemented with random time-shift and random source polarity encoding functions. Numerical tests on the 2D HESS VTI data show that the multisource LSRTM algorithm suppresses migration artifacts, balances the amplitudes, improves image resolution, and reduces crosstalk noise associated with the blended shot gathers. For this example, multisource LSRTM is about three times faster than the conventional RTM method. For the 3D example of the SEG/EAGE salt model, with comparable computational cost, multisource LSRTM produces images with more accurate amplitudes, better spatial resolution, and fewer migration artifacts compared to conventional RTM. The empirical results suggest that the multisource LSRTM can produce more accurate reflectivity images than conventional RTM does with similar or less computational cost. The caveat is that LSRTM image is sensitive to large errors in the migration velocity model. In Chapter 3, the multisource LSRTM algorithm is implemented with frequency selection encoding strategy and applied to marine streamer data, for which traditional random encoding functions are not applicable. The frequency-selection encoding functions are delta functions in the frequency domain, so that all the encoded shots have unique non-overlapping frequency content. Therefore, the receivers can distinguish the wavefield from each shot according to the frequencies. With the frequency-selection encoding method, the computational efficiency of LSRTM is increased so that its cost is

  10. Urban bound migration and rural investment: the case of Mexico.

    Science.gov (United States)

    Silvers, A L; Crosson, P

    1983-02-01

    The authors investigate an agriculturally based policy for improving rural incomes and for retarding the rural-urban migration flow. The production of agricultural goods is characterized by a production function in which output increases with increases in agricultural labor inputs, capital, public infrastructure, land, and technology. Differences among regions in agricultural technology will reflect regional differences in education, the institutionalized form of productive organization, and differences in access to technological information channeled through more technically advanced cities. To pick up the effect of out-migration changes in state agricultural labor supply and upon agricultural output, the state's agricultural out-migration rate is included together with the agricultural labor force. The gross migrant flow between 2 locations is hypothesized to depend upon a set of variables influencing the individual's perception of the economic rate of return to be gained by moving, a set of variables reflecting the individual's propensity to relocate, the labor displacement effects of investments, and the at risk population at 1 location available to migrate. It is also taken into account that individuals differ in their response to information about origin and destination wage differentials and that individuals may or may not perceive a new ecnomic gain from migration but may base the decision on other considerations. Results of a statistical analysis using data from the Mexican census of population for 1960 and 1970 are: 1) size of the rural labor force was negatively associated with agricultural wages, contrary to expectations; 2) small farmers have benefited from the expansion of irrigation in Mexico; and 3) higher urban wages attract migration, and higher growth rate of agricultural income retards rural-urban migration. With respect to the 1950-60 decade both agricultural income and rural out-migration impacts could have been substantial but both the impact

  11. Migration of northern yellowstone elk: Implications of spatial structuring

    Science.gov (United States)

    White, P.J.; Proffitt, K.M.; Mech, L.D.; Evans, S.B.; Cunningham, J.A.; Hamlin, K.L.

    2010-01-01

    Migration can enhance survival and recruitment of mammals by increasing access to higher-quality forage or reducing predation risk, or both. We used telemetry locations collected from 140 adult female elk during 20002003 and 20072008 to identify factors influencing the migration of northern Yellowstone elk. Elk wintered in 2 semidistinct herd segments and migrated 10140 km to at least 12 summer areas in Yellowstone National Park (YNP) and nearby areas of Montana. Spring migrations were delayed after winters with increased snow pack, with earlier migration in years with earlier vegetation green-up. Elk wintering at lower elevations outside YNP migrated an average of 13 days earlier than elk at higher elevations. The timing of autumn migrations varied annually, but elk left their summer ranges at about the same time regardless of elevation, wolf numbers, or distance to their wintering areas. Elk monitored for multiple years typically returned to the same summer (96 fidelity, n 52) and winter (61 fidelity, n 41) ranges. Elk that wintered at lower elevations in or near the northwestern portion of the park tended to summer in the western part of YNP (56), and elk that wintered at higher elevations spent summer primarily in the eastern and northern parts of the park (82). Elk did not grossly modify their migration timing, routes, or use areas after wolf restoration. Elk mortality was low during summer and migration (8 of 225 elk-summers). However, spatial segregation and differential mortality and recruitment between herd segments on the northern winter range apparently contributed to a higher proportion of the elk population wintering outside the northwestern portion of YNP and summering in the western portion of the park. This change could shift wolf spatial dynamics more outside YNP and increase the risk of transmission of brucellosis from elk to cattle north of the park. ?? 2010 American Society of Mammalogists.

  12. Globalization, Migration and Development

    Directory of Open Access Journals (Sweden)

    George, Susan

    2002-01-01

    Full Text Available EnglishMigration may become the most important branch of demography in the earlydecades of the new millennium in a rapidly globalizing world. This paper discusses the causes, costsand benefits of international migration to countries of the South and North, and key issues of commonconcern. International migration is as old as national boundaries, though its nature, volume,direction, causes and consequences have changed. The causes of migration are rooted in the rate ofpopulation growth and the proportion of youth in the population, their education and training,employment opportunities, income differentials in society, communication and transportationfacilities, political freedom and human rights and level of urbanization. Migration benefits the Souththrough remittances of migrants, improves the economic welfare of the population (particularly womenof South countries generally, increases investment, and leads to structural changes in the economy.However, emigration from the South has costs too, be they social or caused by factors such as braindrain. The North also benefits by migration through enhancement of economic growth, development ofnatural resources, improved employment prospects, social development and through exposure toimmigrants' new cultures and lifestyles. Migration also has costs to the North such as of immigrantintegration, a certain amount of destabilization of the economy, illegal immigration, and socialproblems of discrimination and exploitation. Issues common to both North and South include impact onprivate investment, trade, international cooperation, and sustainable development. Both North andSouth face a dilemma in seeking an appropriate balance between importing South's labour or itsproducts and exporting capital and technology from the North.FrenchLa migration est sans doute devenue la partie la plus importante de la démographie des premières décennies du nouveau millénaire dans un monde qui change rapidement. Ce

  13. Migration and Remittances : Recent Developments and Outlook - Transit Migration

    OpenAIRE

    World Bank Group

    2018-01-01

    This Migration and Development Brief reports global trends in migration and remittance flows, as well as developments related to the Global Compact on Migration (GCM), and the Sustainable Development Goal (SDG) indicators for volume of remittances as percentage of gross domestic product (GDP) (SDG indicator 17.3.2), reducing remittance costs (SDG indicator 10.c.1) and recruitment costs (SD...

  14. Comet coma sample return instrument

    Science.gov (United States)

    Albee, A. L.; Brownlee, Don E.; Burnett, Donald S.; Tsou, Peter; Uesugi, K. T.

    1994-01-01

    The sample collection technology and instrument concept for the Sample of Comet Coma Earth Return Mission (SOCCER) are described. The scientific goals of this Flyby Sample Return are to return to coma dust and volatile samples from a known comet source, which will permit accurate elemental and isotopic measurements for thousands of individual solid particles and volatiles, detailed analysis of the dust structure, morphology, and mineralogy of the intact samples, and identification of the biogenic elements or compounds in the solid and volatile samples. Having these intact samples, morphologic, petrographic, and phase structural features can be determined. Information on dust particle size, shape, and density can be ascertained by analyzing penetration holes and tracks in the capture medium. Time and spatial data of dust capture will provide understanding of the flux dynamics of the coma and the jets. Additional information will include the identification of cosmic ray tracks in the cometary grains, which can provide a particle's process history and perhaps even the age of the comet. The measurements will be made with the same equipment used for studying micrometeorites for decades past; hence, the results can be directly compared without extrapolation or modification. The data will provide a powerful and direct technique for comparing the cometary samples with all known types of meteorites and interplanetary dust. This sample collection system will provide the first sample return from a specifically identified primitive body and will allow, for the first time, a direct method of matching meteoritic materials captured on Earth with known parent bodies.

  15. Phobos Sample Return: Next Approach

    Science.gov (United States)

    Zelenyi, Lev; Martynov, Maxim; Zakharov, Alexander; Korablev, Oleg; Ivanov, Alexey; Karabadzak, George

    The Martian moons still remain a mystery after numerous studies by Mars orbiting spacecraft. Their study cover three major topics related to (1) Solar system in general (formation and evolution, origin of planetary satellites, origin and evolution of life); (2) small bodies (captured asteroid, or remnants of Mars formation, or reaccreted Mars ejecta); (3) Mars (formation and evolution of Mars; Mars ejecta at the satellites). As reviewed by Galimov [2010] most of the above questions require the sample return from the Martian moon, while some (e.g. the characterization of the organic matter) could be also answered by in situ experiments. There is the possibility to obtain the sample of Mars material by sampling Phobos: following to Chappaz et al. [2012] a 200-g sample could contain 10-7 g of Mars surface material launched during the past 1 mln years, or 5*10-5 g of Mars material launched during the past 10 mln years, or 5*1010 individual particles from Mars, quantities suitable for accurate laboratory analyses. The studies of Phobos have been of high priority in the Russian program on planetary research for many years. Phobos-88 mission consisted of two spacecraft (Phobos-1, Phobos-2) and aimed the approach to Phobos at 50 m and remote studies, and also the release of small landers (long-living stations DAS). This mission implemented the program incompletely. It was returned information about the Martian environment and atmosphere. The next profect Phobos Sample Return (Phobos-Grunt) initially planned in early 2000 has been delayed several times owing to budget difficulties; the spacecraft failed to leave NEO in 2011. The recovery of the science goals of this mission and the delivery of the samples of Phobos to Earth remain of highest priority for Russian scientific community. The next Phobos SR mission named Boomerang was postponed following the ExoMars cooperation, but is considered the next in the line of planetary exploration, suitable for launch around 2022. A

  16. Migration and European integration of Serbia

    Directory of Open Access Journals (Sweden)

    Lutovac Zoran

    2016-01-01

    Full Text Available This paper focuses on migration in the context of European integration which implies, on the one hand, internal integration, integration within the EU and, on the other hand, the enlargement process related to the countries that have applied to join the EU. The aim is to determine in which way the migration, especially refugee crisis in 2015, had influence on the EU, as a supranational political community, and what was the impact on Serbia which is in the process of integration into the European Union. Migrant crisis has shown that the EU has to confront many different issues including several issues of great importance for its survival and strengthening: how to influence on global processes to a greater extent instead of dealing with the consequences of the global politics of others; how to preserve and keep the values that the EU itself is founded and the values on which should be built upon further construction of the political community and, finally, weather the EU can be transformed in the direction of the United European States, in both the functional and in terms of values, or the EU will move towards deepening of Europe of concentric circles. Faced with extremely complex migration situation, Serbia does not have the appropriate institutional and regulatory framework, nor a political response to a series of complex issues in the area of migration and migration-related issues, such as asylum system, irregular migration, sustainable return of our citizens asylum seekers in EU member states, implementation of the agreement on readmission, the departure of highly educated - brain drain, migration and development, the fight against human trafficking (protection of victims, prevention, criminal prosecution of traffickers, and smuggling of migrants, issues of border management, demarcation and boundary determination (as well as the agreement that should be concluded. Some of these problems migrant crisis has made visible by encouraging coping

  17. Recent trends in human migrations: the case of the Venezuelan Andes.

    Science.gov (United States)

    Suarez, M M; Torrealba, R

    1982-01-01

    studies identified that use demographic, economic, or phychosocial approaches have provided partial explanations of the current status of Andean migrations. The explanations they offer, by not transcending the current reality of the migrants, overlook the historical traits of internal migration. Migratory flows do not spring up suddenly. They result from specific socio-political circumstances which, when closely linked to demographic evidence, serve as a basis for understanding the process. Review of studies on internal migration in the Northern Andes, as presented here, reveals a series of distinguishing characteristics: there are 5 migratory patterns--rural to rural, rural to urban, urban to urban, seasonal worker migration, and return migration, and the predominant pattern has been rural to urban; the demographic data show the importance of rural migrants to urban growth in the region and a complementary loss of population in the rural areas; depopulation of the countryside has been selective; and there is a marked disparity in employment remuneration between rural and urban areas.

  18. La Migracion Como Una Transicion Critica para la Persona en Su Ambiente. Una Interpretacion Organismico Evolutiva. (Migration as a Critical Person-in-Environment Transition: An Organismic-Developmental Interpretation.)

    Science.gov (United States)

    Pacheco, Angel M.; And Others

    In order to explore some of the changes and stresses connected with migration and return migration, a study was conducted among migrants returning from the United States mainland to Puerto Rico. The sample consisted of 75 adolescents participating in a Bilingual Education program in Puerto Rico. Data were collected using Psychological Distance…

  19. THE ROMANIAN MIGRATIONAL EVOLUTION PHENOMENON

    Directory of Open Access Journals (Sweden)

    Cristian Raluca

    2009-05-01

    Full Text Available In our contemporary democratic society the migration phenomenon meets unknown valences in any previous societies. Free will and right to self-determination, much exploited by the XX century society., raised the possibility of interpretation of migration

  20. An Institutional Approach to Bordering in Islands: The Canary Islands on the African-European Migration Routes

    Directory of Open Access Journals (Sweden)

    Dirk Godenau

    2012-05-01

    Full Text Available Islands play a significant role in international irregular maritime migration. Frequently they are part of maritime interstitial spaces between states, and their location, combined with institutional membership, makes them part of international migration routes and subject to border management strategies. In this paper borders are analysed as social institutions used for regulating relative permeability through rules of entry and exit for persons, goods and capital. Borders institutionalize territoriality and are politically implemented by states. They are selective, also in migration, and irregular border transit is not always indicative of an inability to control. The Canary Islands are used as an illustrative example of how border management at the southern edge of the European Union has evolved towards more coercive deterrence and tighter surveillance. The Canary Islands experienced irregular maritime immigration from the west African coasts during the first decade of the 21st century and most of these migrants intended to use the islands as transit space towards the European continent. Increasing surveillance in countries of origin, enforcement of border controls and stricter return policies were used to stop flows. The so-called “cayuco crisis” in 2006 induced institutional change in border management and forced the active involvement of the EU through FRONTEX.

  1. International migration and the gender

    OpenAIRE

    Koropecká, Markéta

    2010-01-01

    My bachelor thesis explores the connection between international migration and gender. Gender, defined as a social, not a biological term, has a huge impact on the migration process. Statistics and expert studies that have been gender sensitive since 1970s demonstrate that women form half of the amount of the international migrants depending on the world region and representing a wide range of the kinds of international migration: family formation and reunification, labour migration, illegal ...

  2. The commercialization of migration.

    Science.gov (United States)

    Abrera-mangahas, M A

    1989-01-01

    International migration is not new to the Philippines. In the recent outflow of contract workers to the Middle East, there is a shift from individual and family initiated migrations to the more organized, highly commercial variety. While profit-taking intermediaries have played some role in the past, the increase in the number and influence of these intermediaries has altered the story of migration decision-making. In 1975, the signing of the bilateral labor agreement between the governments of Iran and the Philippines signalled the rising demand for Filipino contract workers. From 1970 to 1975, the number of Asian migrant workers in the Gulf countries rose from about 120,000 to 370,000. These figures rose dramatically to 3.3 million in 1985. The growing share of organized and commercialized migration has altered migration decision making. Primarily, intermediaries are able to broaden access to foreign job and high wage opportunities. Commercialization effectively raises the transaction costs for contract migration. Studies on recruitment costs and fees show that self-solicited foreign employment costs less than employment obtained through recruitment agents and intermediaries. The difference in the 2 prices is due, not only to overhead costs of intermediation, but more importantly to the rent exacted by agents from having job information and placement rights. In the Philippines in October 1987 the average placement fee was P8000, greatly exceeding the mandated maximum fee level of P5000. This average is understated because the computation includes the 17% who do not pay any fees. The widespread and popular view of recruitment intermediaries is negative, dominated by images of abuses and victims. Private intermediaries and the government bureaucracy need each other. Intermediaries need government; their consistent demand for incentives and protection is indicative. On the other hand, government expands its supervision of control of overseas employment via the

  3. Consequences of migration and remittances for Mexican transnational communities.

    Science.gov (United States)

    Conway, D; Cohen, J H

    1998-01-01

    "Our aims in this paper are to broaden explanation of remittance expenditures and to evaluate the positive contributions of remittances, return migrants, or circulating sojourners. Specifically focusing on the situation in ¿home' communities, we illustrate the multifaceted consequences of remittances and migration, emphasizing positive nonmonetary and social impacts." Data are from ethnographic research carried out in 1992-1993 in Santa Ana del Valle, Oaxaca, Mexico. excerpt

  4. Optimal size at seaward migration in an anadromous salmonid

    OpenAIRE

    Jonsson, Bror; Jonsson, Marius; Jonsson, Nina

    2016-01-01

    In this study, the probabilistic reaction norm was calculated for length at different ages of smolting before seaward migration of Atlantic salmon Salmo salar spawning in the Norwegian River Imsa. The reaction norm was compared with the optimal length at smolting estimated as the product of survival and female fecundity on the return, given their length at smolting. Logistic regression analysis on pre-migratory and migratory fish was used to estimate the probabilistic reaction norm. Length at...

  5. International Student Migration to Norway. Who stays and who leaves?

    OpenAIRE

    Tran, Lea Nga Thanh

    2014-01-01

    International student migration to Norway has markedly increased during the past 20 years. This inflow has caused the Norwegian authorities to shed light on the topic. Until 2001, it was expected from the Norwegian authorities that international students return home after graduation. After the 21th century several policy changes occurred to attract more international students to Norway, and making it easier for international students to obtain a work permit after their studies. This thesis an...

  6. Distribution and migration chronology of Eastern population sandhill cranes

    Science.gov (United States)

    Fronczak, David L.; Andersen, David; Hanna, Everett E.; Cooper, Thomas R.

    2017-01-01

    The Eastern Population (EP) of greater sandhill cranes (Antigone canadensis tabida; cranes) is expanding in size and geographic range. Little information exists regarding the geographic extent of breeding, migration, and wintering ranges, migration chronology, or use of staging areas for cranes in the EP. To obtain these data, we attached solar global positioning system (GPS) platform transmitting terminals (PTTs) to 42 sandhill cranes and monitored daily locations from December 2009 through August 2014. On average, tagged cranes settled in summer areas during late‐March in Minnesota (7%), Wisconsin (29%), Michigan, USA (21%), and Ontario, Canada (38%) and arrived at their winter terminus beginning mid‐December in Indiana (15%), Kentucky (3%), Tennessee (45%), Georgia (5%), and Florida (32%). Cranes initiated spring migration beginning mid‐February to their respective summer areas on routes similar to those used during fall migration. Twenty‐five marked cranes returned to the same summer area after a second spring migration, of which 19 (76%) settled cranes in the EP, we estimated that approximately 29–31% of cranes that summered in both Wisconsin and the Lower Peninsula of Michigan were not in areas included in the survey. The information we collected on crane movements provides insight into distribution and migration chronology that will aid in assessment of the current USFWS fall survey. In addition, information on specific use sites can assist state and federal managers to identify and protect key staging and winter areas particularly during current and future recreational harvest seasons.

  7. Migration signatures across the decades: Net migration by age in U.S. counties, 1950-2010

    Directory of Open Access Journals (Sweden)

    Richelle L. Winkler

    2015-05-01

    Full Text Available Background: Migration is the primary population redistribution process in the United States. Selective migration by age, race/ethnic group, and spatial location governs population integration, affects community and economic development, contributes to land use change, and structures service needs. Objective: Delineate historical net migration patterns by age, race/ethnic, and rural-urban dimensions for United States counties. Methods: Net migration rates by age for all US counties are aggregated from 1950−2010, summarized by rural-urban location and compared to explore differential race/ethnic patterns of age-specific net migration over time. Results: We identify distinct age-specific net migration 'signatures' that are consistent over time within county types, but different by rural-urban location and race/ethnic group. There is evidence of moderate population deconcentration and diminished racial segregation between 1990 and 2010. This includes a net outflow of Blacks from large urban core counties to suburban and smaller metropolitan counties, continued Hispanic deconcentration, and a slowdown in White counterurbanization. Conclusions: This paper contributes to a fuller understanding of the complex patterns of migration that have redistributed the U.S. population over the past six decades. It documents the variability in county age-specific net migration patterns both temporally and spatially, as well as the longitudinal consistency in migration signatures among county types and race/ethnic groups.

  8. Youth Labor Migration in Nepal

    OpenAIRE

    Bossavie, Laurent; Denisova, Anastasiya

    2018-01-01

    This descriptive study investigates internal and external labor migration by Nepalese youth. External labor migration is separated into the flow to India, which is unregulated, and the flow to other countries, which typically takes the form of temporary contract migration to countries with bilateral labor agreements with Nepal (referred to in Nepal as foreign employment). The study finds t...

  9. Musei del migration heritage / Migration heritage museums

    Directory of Open Access Journals (Sweden)

    Patrizia Dragoni

    2015-01-01

    Since the second half of the 1960s of the 20th century, a profound cultural innovation was accompanied to the radical change in the social, political and economic climate. The anthropological notion of culture as opposed to idealistic vision, the unusual and strong interest in material culture, the enunciation of the concept of cultural property by the Franceschini Commission, the luck of the Public History bring a change of the disciplinary statutes of historical sciences, which begin to attend to social history, focusing on the spontaneous sources of information and initiating experiences of oral history. To all this a remarkable transformation of the themes and of the social function of museums is added. This paper illustrates, in relation to this more general context, the foundation and the dissemination of museums dedicated to the history of migration in Italy and in the world, enunciates their possible social utility for the integration of present migrants in Italy and illustrates, by way of example, the museum recently opened in Recanati.

  10. Religion, migration og integration

    DEFF Research Database (Denmark)

    Borup, Jørn

    2010-01-01

    Sammenhængen mellem religion og integration har de sidste år været genstand for debat. Artiklen kommer ind på begreber og sammenhænge relateret til området (migration, diaspora, assimilation, etnicitet, kultur) og ser på religionens mulige rolle som negativ eller positiv ressource i integrationss......Sammenhængen mellem religion og integration har de sidste år været genstand for debat. Artiklen kommer ind på begreber og sammenhænge relateret til området (migration, diaspora, assimilation, etnicitet, kultur) og ser på religionens mulige rolle som negativ eller positiv ressource i...

  11. Grain boundary migration

    International Nuclear Information System (INIS)

    Dimitrov, O.

    1975-01-01

    Well-established aspects of grain-boundary migration are first briefly reviewed (influences of driving force, temperature, orientation and foreign atoms). Recent developments of the experimental methods and results are then examined, by considering the various driving of resistive forces acting on grain boundaries. Finally, the evolution in the theoretical models of grain-boundary motion is described, on the one hand for ideally pure metals and, on the other hand, in the presence of solute impurity atoms [fr

  12. Ventriculoperitoneal Shunt Migration

    Directory of Open Access Journals (Sweden)

    Justin P Puller

    2017-01-01

    Full Text Available History of present illness: A 40-year-old female presented to our ED with left upper abdominal pain and flank pain. The pain had begun suddenly 2 hours prior when she was reaching into a freezer to get a bag of frozen vegetables. She described the pain as sharp, constant, severe, and worse with movements and breathing. The pain radiated to the left shoulder. On review of systems, the patient had mild dyspnea and nausea. She denied fever, chills, headache, vision changes, vomiting, or urinary symptoms. Her medical history was notable for obstructive sleep apnea, gastroesophageal reflux disease, arthritis, fibromyalgia, depression, obesity, and idiopathic intracranial hypertension. For the latter, she had a VP (ventriculoperitoneal shunt placed 14 years prior to this visit. She had a history of 2 shunt revisions, the most recent 30 days before this ED visit. Significant findings: An immediate post-op abdominal x-ray performed after the patient’s VP shunt revision 30 days prior to this ED visit reveals the VP shunt tip in the mid abdomen. A CT of the abdomen performed on the day of the ED visit reveals the VP shunt tip interposed between the spleen and the diaphragm. Discussion: VP shunts have been reported to migrate to varied locations in the thorax and abdomen. Incidence of abdominal complications of VP shunt placement ranges from 10%-30%, and can include pseudocyst formation, migration, peritonitis, CSF ascites, infection, and viscus perforation. Incidence of distal shunt migration is reported as 10%, and most previously reported cases occurred in pediatric patients.1 A recent retrospective review cited BMI greater than thirty and previous shunt procedure as risk factors for distal shunt migration.2 The patient in the case presented had a BMI of 59 and 3 previous shunt procedures.

  13. Conservation physiology of animal migration

    Science.gov (United States)

    Lennox, Robert J.; Chapman, Jacqueline M.; Souliere, Christopher M.; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D.; Cooke, Steven J.

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  14. Many Faces of Migrations

    Directory of Open Access Journals (Sweden)

    Milica Antić Gaber

    2013-12-01

    We believe that in the present thematic issue we have succeeded in capturing an important part of the modern European research dynamic in the field of migration. In addition to well-known scholars in this field several young authors at the beginning their research careers have been shortlisted for the publication. We are glad of their success as it bodes a vibrancy of this research area in the future. At the same time, we were pleased to receive responses to the invitation from representatives of so many disciplines, and that the number of papers received significantly exceeded the maximum volume of the journal. Recognising and understanding of the many faces of migration are important steps towards the comprehensive knowledge needed to successfully meet the challenges of migration issues today and even more so in the future. It is therefore of utmost importance that researchers find ways of transferring their academic knowledge into practice – to all levels of education, the media, the wider public and, of course, the decision makers in local, national and international institutions. The call also applies to all authors in this issue of the journal.

  15. Market Timing : A Decomposition of Mutual Fund Returns

    NARCIS (Netherlands)

    Swinkels, L.A.P.; van der Sluis, P.J.; Verbeek, M.J.C.M.

    2003-01-01

    We decompose the conditional expected mutual fund return in ve parts.Two parts, selectivity and expert market timing, can be attributed to manager skill, and three to variation in market exposure that can be achieved by private investors as well.The dynamic model that we use to estimate the relative

  16. Impact of ER520, a candidate of selective estrogen receptor modulators, on in vitro cell growth, migration, invasion, angiogenesis and in vivo tumor xenograft of human breast cancer cells.

    Science.gov (United States)

    Wang, Lijun; Wang, Ying; Du, Huaqing; Jiang, Yao; Tang, Zhichao; Liu, Hongyi; Xiang, Hua; Xiao, Hong

    2015-12-01

    ER520, a derivative of indenoisoquinoline, is a patented compound. This study was designed to screen its biological properties and to evaluate its antineoplastic and antiangiogenic effect. Western blot was employed to monitor the ERα and ERβ protein expression in human breast cancer MCF-7 cells and endometrial carcinoma Ishikawa cells. MTT assay was employed to determine cell proliferation. Cell adhesion, scratch and Transwell assay were utilized to estimate the ability of cellular adhesion, migration and invasion. ELISA kit was applied to detect the VEGF products in culture medium. In addition, the inhibitory effect of ER520 on the vessel-like construction of HUVEC cells and the angiogenesis of chicken embryos was investigated. The efficiency of ER520 on tumor growth in nude mice was also assessed. ER520 inhibited the expression of ERα in MCF-7 and Ishikawa cells, while it increased ERβ protein level. ER520 also suppressed the proliferation of MCF-7 and Ishikawa cells. Due to its remarkably negative role in cell adhesion, migration and invasion, ER520 showed a potential ability of inhibiting tumor metastasis. Meanwhile, ER520 reduced the VEGF secretion of MCF-7 and Ishikawa cells, prevented the formation of VEGF-stimulated tubular structure and the cell migration of HUVEC cells, and inhibited the angiogenesis of chicken chorioallantoic membrane. Animal experiment also demonstrated that ER520 could frustrate the in vivo tumor growth and the inhibitory ratio was 48.5 % compared with control group. Our findings indicate that ER520 possesses the competence to be a candidate against breast cancer and angiogenesis.

  17. Migration Decision-Making among Mexican Youth: Individual, Family, and Community Influences.

    Science.gov (United States)

    Tucker, Christine M; Torres-Pereda, Pilar; Minnis, Alexandra M; Bautista-Arredondo, Sergio A

    2013-05-07

    We explored migration decisions using in-depth, semi-structured interviews with male and female youth ages 14 to 24 (n=47) from two Mexican communities, one with high and one with low U.S. migration density. Half were return migrants and half were non-migrants with relatives in the U.S. Migrant and non-migrant youth expressed different preferences, especially in terms of education and their ability to wait for financial gain. Reasons for migration were mostly similar across the two communities; however, the perceived risk of the migration journey was higher in the low density migration community while perceived opportunities in Mexico were higher in the high density migration community. Reasons for return were related to youths' initial social and economic motivations for migration. A greater understanding of factors influencing migration decisions may provide insight into the vulnerability of immigrant youth along the journey, their adaptation process in the U.S., and their reintegration in Mexico.

  18. Void migration, coalescence and swelling in fusion materials

    International Nuclear Information System (INIS)

    Cottrell, G.A.

    2003-01-01

    A recent analysis of the migration of voids and bubbles, produced in neutron irradiated fusion materials, is outlined. The migration, brought about by thermal hopping of atoms on the surface of a void, is normally a random Brownian motion but, in a temperature gradient, can be slightly biassed up the gradient. Two effects of such migrations are the transport of voids and trapped transmutation helium atoms to grain boundaries, where embrittlement may result; and the coalescence of migrating voids, which reduces the number of non-dislocation sites available for the capture of knock-on point defects and thereby enables the dislocation bias process to maintain void swelling. A selection of candidate fusion power plant armour and structural metals have been analysed. The metals most resistant to void migration and its effects are tungsten and molybdenum. Steel and beryllium are least so and vanadium is intermediate

  19. STRUCTURAL ECONOMIC CHANGE AND INTERNATIONAL MIGRATION FROM MEXICO AND POLAND

    Science.gov (United States)

    Massey, Douglas S.; Kalter, Frank; Pren, Karen A.

    2010-01-01

    In this article we use uniquely comparable data sets from two very different settings to examine how exogenous economic transformations affect the likelihood and selectivity of international out-migration. Specifically, we use data from the Mexican Migration Project to construct event history files predicting first U.S. trips from seven communities in the state of Veracruz, which until recently sent very few migrants abroad. Similarly, using data from the Polish Migration Project, we derive comparable event history files predicting first trips to Germany from four Polish communities, which also sent few migrants abroad before the 1980s. Our analyses suggest that the onset of structural adjustment in both places had a significant effect in raising the probability of international migration, even when controlling for a set of standard variables specified by other theories to influence migration propensity, such as the size of the binational income gap and various indicators of human and social capital. PMID:21765550

  20. Migration Process Evolution in Europe

    Directory of Open Access Journals (Sweden)

    Carmen Tudorache

    2006-08-01

    Full Text Available The migration phenomenon has always existed, fluctuating by the historic context, the economic, political, social and demographic disparities between the Central and East European countries and the EU Member States, the interdependencies between the origin and receiving countries and the European integration process evolutions. In the European Union, an integrated and inclusive approach of the migration issue is necessary. But a common policy on migration rests an ambitious objective. A common approach of the economic migration management and the harmonization of the migration policies of the Member States represented a challenge for the European Union and will become urgent in the future, especially due to the demographic ageing.

  1. Migrations in Slovenian geography textbooks

    Directory of Open Access Journals (Sweden)

    Jurij Senegačnik

    2013-12-01

    Full Text Available In Slovenia, the migrations are treated in almost all geographical textbooks for different levels of education. In the textbooks for the elementary school from the sixth to ninth grade, students acquire knowledge of the migrations by the inductive approach. Difficulty level of treatment and quantity of information are increasing by the age level. In the grammar school program a trail of gaining knowledge on migration is deductive. Most attention is dedicated to migrations in general geography textbooks. The textbooks for vocational and technical school programs deal with migrations to a lesser extent and with different approaches.

  2. Financial Integration and Asset Returns

    OpenAIRE

    P Martin; H Rey

    2000-01-01

    The paper investigates the impact of financial integration on asset return, risk diversification and breadth of financial markets. We analyse a three-country macroeconomic model in which (i) the number of financial assets is endogenous; (ii) assets are imperfect substitutes; (iii) cross-border asset trade entails some transaction costs; (iv) the investment technology is indivisible. In such an environment, lower transaction costs between two financial markets translate to higher demand for as...

  3. Returning to work after disability.

    Science.gov (United States)

    Quinn, P Roger

    2002-06-01

    After a workplace injury or disability, there is a period of hardship and adjustment for the injured party as well as all stakeholders in the workers' compensation process. Ultimately, however, return to work is considered. The author reviews this often challenging exercise from the Canadian perspective and stresses the need for timely intervention, honest communication, the coordination of information and resources--and the need for flexibility. A case study on low back pain is included.

  4. Relations between information and communication technologies and international migration

    Directory of Open Access Journals (Sweden)

    Lukić Vesna

    2017-01-01

    asylum seekers have recently started. That can also be said for the research, where ICTs serve for gaining knowledge on migrants and attitudes towards immigrants. Although not voluminous, academic literature on the use and implications of ICTs use in the migration process in Serbia points to greater use of ICTs by certain groups of migrants (long-term settled refugees from former Yugoslavia in relation to the local population. There are also generational and gender differences in the use of ICTs by migrants. When it comes to transit asylum seekers in Serbia, the use of ICTs at various stages of migration and for various purposes (among them are the selection of the country of destination, the route of movement, but also contact with other migrants and smugglers is observed. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III47006

  5. Tick size and stock returns

    Science.gov (United States)

    Onnela, Jukka-Pekka; Töyli, Juuso; Kaski, Kimmo

    2009-02-01

    Tick size is an important aspect of the micro-structural level organization of financial markets. It is the smallest institutionally allowed price increment, has a direct bearing on the bid-ask spread, influences the strategy of trading order placement in electronic markets, affects the price formation mechanism, and appears to be related to the long-term memory of volatility clustering. In this paper we investigate the impact of tick size on stock returns. We start with a simple simulation to demonstrate how continuous returns become distorted after confining the price to a discrete grid governed by the tick size. We then move on to a novel experimental set-up that combines decimalization pilot programs and cross-listed stocks in New York and Toronto. This allows us to observe a set of stocks traded simultaneously under two different ticks while holding all security-specific characteristics fixed. We then study the normality of the return distributions and carry out fits to the chosen distribution models. Our empirical findings are somewhat mixed and in some cases appear to challenge the simulation results.

  6. Women work migration and its influence at the gendered family roles

    OpenAIRE

    Mohylová, Michaela

    2014-01-01

    The aim of my thesis is to discuss the process of adaptation of family members in times of mothers work migration and when she returns back home. In following text I focus on the description of new strategies by which the family copes with a situation, which stands against the concept of life in a traditional society with close interpersonal relationships. I also focus on the consequences of long term work migration and creation of new projects for following family cohabitation.

  7. “International Migration and Gender Discrimination among Children Left Behind”

    Science.gov (United States)

    Antman, Francisca M.

    2012-01-01

    This paper considers how international migration of the head of household affects the allocation of resources toward boys relative to girls within households remaining in the home country. I address the endogeneity of migration with a differences-in-differences style regression model that compares those households in which migrants have already returned home with those in which migrants are still away. The evidence suggests that while the head of household is away a greater fraction of resources are spent on girls relative to boys, but upon his return, this pattern is reversed. PMID:23239896

  8. Security and skills: the two key issues in health worker migration

    Directory of Open Access Journals (Sweden)

    Posy Bidwell

    2014-07-01

    Full Text Available Background: Migration of health workers from Africa continues to undermine the universal provision of quality health care. South Africa is an epicentre for migration – it exports more health workers to high-income countries than any other African country and imports health workers from its lower-income neighbours to fill the gap. Although an inter-governmental agreement in 2003 reduced the very high numbers migrating from South Africa to the United Kingdom, migration continues to other high-income English-speaking countries and few workers seem to return although the financial incentive to work abroad has lessened. A deeper understanding of reasons for migration from South Africa and post-migration experiences is therefore needed to underpin policy which is developed in order to improve retention within source countries and encourage return. Methods: Semi-structured interviews were conducted with 16 South African doctors and nurses who had migrated to the United Kingdom. Interviews explored factors influencing the decision to migrate and post-migration experiences. Results: Salary, career progression, and poor working conditions were not major push factors for migration. Many health workers reported that they had previously overcome these issues within the South African healthcare system by migrating to the private sector. Overwhelmingly, the major push factors were insecurity, high levels of crime, and racial tension. Although the wish to work and train in what was perceived to be a first-class care system was a pull factor to migrate to the United Kingdom, many were disappointed by the experience. Instead of obtaining new skills, many (particularly nurses felt they had become ‘de-skilled’. Many also felt that working conditions and opportunities for them in the UK National Health Service (NHS compared unfavourably with the private sector in South Africa. Conclusions: Migration from South Africa seems unlikely to diminish until the major

  9. Security and skills: the two key issues in health worker migration.

    Science.gov (United States)

    Bidwell, Posy; Laxmikanth, Pallavi; Blacklock, Claire; Hayward, Gail; Willcox, Merlin; Peersman, Wim; Moosa, Shabir; Mant, David

    2014-01-01

    Migration of health workers from Africa continues to undermine the universal provision of quality health care. South Africa is an epicentre for migration--it exports more health workers to high-income countries than any other African country and imports health workers from its lower-income neighbours to fill the gap. Although an inter-governmental agreement in 2003 reduced the very high numbers migrating from South Africa to the United Kingdom, migration continues to other high-income English-speaking countries and few workers seem to return although the financial incentive to work abroad has lessened. A deeper understanding of reasons for migration from South Africa and post-migration experiences is therefore needed to underpin policy which is developed in order to improve retention within source countries and encourage return. Semi-structured interviews were conducted with 16 South African doctors and nurses who had migrated to the United Kingdom. Interviews explored factors influencing the decision to migrate and post-migration experiences. Salary, career progression, and poor working conditions were not major push factors for migration. Many health workers reported that they had previously overcome these issues within the South African healthcare system by migrating to the private sector. Overwhelmingly, the major push factors were insecurity, high levels of crime, and racial tension. Although the wish to work and train in what was perceived to be a first-class care system was a pull factor to migrate to the United Kingdom, many were disappointed by the experience. Instead of obtaining new skills, many (particularly nurses) felt they had become 'de-skilled'. Many also felt that working conditions and opportunities for them in the UK National Health Service (NHS) compared unfavourably with the private sector in South Africa. Migration from South Africa seems unlikely to diminish until the major concerns over security, crime, and racial tensions are resolved

  10. On the interrelations between migration and commuting

    Directory of Open Access Journals (Sweden)

    Lukić Vesna

    2013-01-01

    Full Text Available In this paper, we emphasise the significance of studying the interrelations between commuting and migration. The aim of the paper is to point out the factors which affect these interrelations (demographic and socio-economic characteristics of migrants and commuters, labour market, real estate market, information, life style, etc., with the special emphasis on the role of commuting distance onto the chosen mobility type. Besides theorethical frameworks and results of the selected foreign researches up to date, the overview of research of interrelations between migration and commuting in Serbia has also been presented. While earlier studies conducted by Gawryszenski (1978, Termote (1980 and Reitsma&Vergoossen (1987 pointed to the replacement of migration types between each other within country, in recent literature the interaction between migration and commuting has been studied in a trans-boundary context of the contemporary EU. Modern trend of long distance commuting instead of migration and the concept of substitution/replacement regarding migration and commuting have also been discussed. In Serbia, there is a positive correlation between commuting outflows and immigration in rural settlements of Vojvodina province. Namely, commuting and migration are complement, which is the characteristic of both processes sub-urbanisation and ex-urbanisation (Lukić, 2012. In addition to ownership of real estate and previous migration experience, marital status influenced the chosen mobility type in Serbia as well. Adjustment to changes of Serbian labour market is mostly conducted via migration (Miletić, Lukić, Miljanović, 2011. Interrelations between migration and commuting are very significant due to the tendency of transformation of some commuters into migrants. This process has its consequences, both on demographic as well as the overall socio-economic development of the area of commuters’ origin and destination. However, even though the surveys

  11. Migration study of americium in porous medium

    International Nuclear Information System (INIS)

    Tanaka, Tadao; Ogawa, Hiromichi

    1999-01-01

    Migration experiments of 241 Am 3+ had been performed by a column system, to investigate migration behavior of 241 Am through a column packed porous sedimentary materials: a coastal sandy soil and a reddish soil. Most 241 Am loaded into the column packed the reddish soil sorbed on the influent edge of the column. In the case of the sandy soil, however, considerable amount of 241 Am was passed through the column. This shows that there is colloidal 241 Am species which may move without effective interaction with the sandy soil. Such a migration behavior of colloidal 241 Am in the sandy soil column could be evaluated by a sorption model based on filtration theory. Sorption mechanisms of 241 Am on the sedimentary materials were examined by a chemical extraction method, for 241 Am sorbed on the sandy soil and the reddish soil at any sections in the column. The 241 Am sorbed on the reddish soil was mainly controlled by a reversible ion exchange reaction. On the other hand, the 241 Am sorbed on the sandy soil ws controlled by irreversible reactions, such as the selective chemical sorptions onto Fe and Mn oxyhydroxide/oxide. The experimental results support that the migration of 241 Am in the reddish soil layer can be estimated by using the K d , whereas that in the sandy soil can not be explained by the K d concept. (author)

  12. Migration magnet: The role of work experience in rural-urban wage differentials

    OpenAIRE

    Michaelsen, Maren; Haisken-DeNew, John

    2015-01-01

    This study uses the nationally representative Mexican Family Life Survey (MxFLS) to identify systematic differences in earnings returns to human capital endowments for formal and informal sector workers in rural and urban Mexico. Returns to experience are critical in explaining the large urban wage gap in a Blinder-Oaxaca decomposition and indeed drive pull migration from the rural informal sector to the urban informal sector, exacerbating urban population congestion in already over-crowded m...

  13. Immigration impacts on internal migration of the poor: 1990 census evidence for U.S. states.

    Science.gov (United States)

    Frey, W H

    1995-09-01

    "This article presents newly-available migration data from the 1990 U.S. census to assess immigration and internal migration components as they affect state poverty populations. New immigrant waves are heavily focused on only a few 'port-of-entry' states. It is suggested that these immigrants have begun to impact upon internal migration into and out of these 'high immigration states', and have also altered the national system of internal migration patterns. This article addresses three questions: How do the magnitudes of poverty population out-migration from high immigration states compare with those of other states? Is this out-migration selective on particular social and demographic groups? Is immigration a significant determinant of internal migration of the poor population? The results of this analysis are consistent with the view that recent, focused immigration is associated with out-migration among a state's poor longer-term residents." excerpt

  14. Japanese migration in contemporary Japan: economic segmentation and interprefectural migration.

    Science.gov (United States)

    Fukurai, H

    1991-01-01

    This paper examines the economic segmentation model in explaining 1985-86 Japanese interregional migration. The analysis takes advantage of statistical graphic techniques to illustrate the following substantive issues of interregional migration: (1) to examine whether economic segmentation significantly influences Japanese regional migration and (2) to explain socioeconomic characteristics of prefectures for both in- and out-migration. Analytic techniques include a latent structural equation (LISREL) methodology and statistical residual mapping. The residual dispersion patterns, for instance, suggest the extent to which socioeconomic and geopolitical variables explain migration differences by showing unique clusters of unexplained residuals. The analysis further points out that extraneous factors such as high residential land values, significant commuting populations, and regional-specific cultures and traditions need to be incorporated in the economic segmentation model in order to assess the extent of the model's reliability in explaining the pattern of interprefectural migration.

  15. Crew emergency return vehicle - Electrical power system design study

    Science.gov (United States)

    Darcy, E. C.; Barrera, T. P.

    1989-01-01

    A crew emergency return vehicle (CERV) is proposed to perform the lifeboat function for the manned Space Station Freedom. This escape module will be permanently docked to Freedom and, on demand, will be capable of safely returning the crew to earth. The unique requirements that the CERV imposes on its power source are presented, power source options are examined, and a baseline system is selected. It consists of an active Li-BCX DD-cell modular battery system and was chosen for the maturity of its man-rated design and its low development costs.

  16. Labour migration from Turkey.

    Science.gov (United States)

    Uner, S

    1988-01-01

    This study is concerned with Turkish labor migration to Western Europe. Earlier and recent patterns of labor migration, characteristics of migrants by occupation, area of destination, and by geographical origins are discussed. Economic and demographic consequences of labor migration are also analyzed. It is estimated that Turkey's population will reach 73 million at the year 2000 with the present growth rate of 2.48% annually. Considering the efforts made to slow down the present high fertility rates and assuming that the decrease in labor force participation during 1970-1980 continues, the author concludes that the labor supply will increase with a growth rate of 2% annually for the next 13-15 years. Thus, the labor supply will reach 26.6 million people in the year 2000 from the 1980 level of 17.8 million. Assuming also that the income/employment elasticity of .25 which was observed throughout the period of 1960-1980 will not change until 2000, the annual growth rate of employment may be estimated as 1.5%. Thus, the number of people employed will reach 20 million in the year 1990 and 23.2 million in the year 2000. 8.8 million people will join the labor market as new entrants between 1980 and 2000. Only 6 million people out of 8.8 million will be employed. Thus, in the year 2000, it is estimated that 2.8 million new unemployed people will be added to the already open unemployment figure 1980 census data give the number of unemployed as .6 million people. Adding the 2.8 million new unemployed to this figure totals 3.4 million unemployed in 2000. The State Planning Organization's estimate of labor surplus for 1980 was 2.5 million people. When 2.8 million unemployed people are added to this figure, the labor surplus for the year 2000 reaches 5.3 million people.

  17. Probabilistic migration modelling focused on functional barrier efficiency and low migration concepts in support of risk assessment.

    Science.gov (United States)

    Brandsch, Rainer

    2017-10-01

    Migration modelling provides reliable migration estimates from food-contact materials (FCM) to food or food simulants based on mass-transfer parameters like diffusion and partition coefficients related to individual materials. In most cases, mass-transfer parameters are not readily available from the literature and for this reason are estimated with a given uncertainty. Historically, uncertainty was accounted for by introducing upper limit concepts first, turning out to be of limited applicability due to highly overestimated migration results. Probabilistic migration modelling gives the possibility to consider uncertainty of the mass-transfer parameters as well as other model inputs. With respect to a functional barrier, the most important parameters among others are the diffusion properties of the functional barrier and its thickness. A software tool that accepts distribution as inputs and is capable of applying Monte Carlo methods, i.e., random sampling from the input distributions of the relevant parameters (i.e., diffusion coefficient and layer thickness), predicts migration results with related uncertainty and confidence intervals. The capabilities of probabilistic migration modelling are presented in the view of three case studies (1) sensitivity analysis, (2) functional barrier efficiency and (3) validation by experimental testing. Based on the predicted migration by probabilistic migration modelling and related exposure estimates, safety evaluation of new materials in the context of existing or new packaging concepts is possible. Identifying associated migration risk and potential safety concerns in the early stage of packaging development is possible. Furthermore, dedicated material selection exhibiting required functional barrier efficiency under application conditions becomes feasible. Validation of the migration risk assessment by probabilistic migration modelling through a minimum of dedicated experimental testing is strongly recommended.

  18. Urbanization, Migration, Information

    Directory of Open Access Journals (Sweden)

    Konstantin Lidin

    2016-05-01

    Full Text Available In the contemporary world urbanization becomes a large-scale process. Huge flows of people migrate from poorer districts to the cities with a higher level of consumption. It takes migrants about 15-25 years to give up their traditional ascetic way of life. In this period the ‘new citizens’ try to arrange compact settlements with an archaic way of life, insanitary conditions, high criminogenity and an authoritative local self-government. The processes of formation and decay of the ascetic enclave are viewed through the example of the ‘Shanghai’ trading neighborhood in Irkutsk.

  19. Neuronal Migration and Neuronal Migration Disorder in Cerebral Cortex

    OpenAIRE

    SUN, Xue-Zhi; TAKAHASHI, Sentaro; GUI, Chun; ZHANG, Rui; KOGA, Kazuo; NOUYE, Minoru; MURATA, Yoshiharu

    2002-01-01

    Neuronal cell migration is one of the most significant features during cortical development. After final mitosis, neurons migrate from the ventricular zone into the cortical plate, and then establish neuronal lamina and settle onto the outermost layer, forming an "inside-out" gradient of maturation. Neuronal migration is guided by radial glial fibers and also needs proper receptors, ligands, and other unknown extracellular factors, requests local signaling (e.g. some emitted by the Cajal-Retz...

  20. Anisotropy signature in extended images from reverse-time migration

    KAUST Repository

    Sava, Paul

    2012-11-04

    Reverse-time migration can accurately image complex geologic structures in anisotropic media. Extended images at selected locations in the earth, i.e. at common-image-point gathers (CIPs), carry enough information to characterize the angle-dependent illumination and to provide measurements for migration velocity analysis. Furthermore, inaccurate anisotropy leaves a distinctive signature in CIPs, which can be used to evaluate anisotropy through techniques similar to the ones used in conventional wavefield tomography.

  1. Anisotropy signature in extended images from reverse-time migration

    KAUST Repository

    Sava, Paul; Alkhalifah, Tariq Ali

    2012-01-01

    Reverse-time migration can accurately image complex geologic structures in anisotropic media. Extended images at selected locations in the earth, i.e. at common-image-point gathers (CIPs), carry enough information to characterize the angle-dependent illumination and to provide measurements for migration velocity analysis. Furthermore, inaccurate anisotropy leaves a distinctive signature in CIPs, which can be used to evaluate anisotropy through techniques similar to the ones used in conventional wavefield tomography.

  2. Circadian flight schedules in night-migrating birds caught on migration.

    Science.gov (United States)

    Coppack, Timothy; Becker, Simon F; Becker, Philipp J J

    2008-12-23

    Many species of migratory birds migrate in a series of solitary nocturnal flights. Between flights, they stop to rest and refuel for the next segment of their journey. The mechanism controlling this behaviour has long remained elusive. Here, we show that wild-caught migratory redstarts (Phoenicurus phoenicurus) are consistent in their flight scheduling. An advanced videographic system enabled us to determine the precise timing of flight activity in redstarts caught at a northern European stopover site during their return trip from Africa. Birds were held captive for three days in the absence of photoperiodic cues (constant dim light) and under permanent food availability. Despite the absence of external temporal cues, birds showed clear bimodal activity patterns: intense nocturnal activity alternating with diurnal foraging and resting periods. The onset of their migratory activity coincided with the time of local sunset and was individually consistent on consecutive nights. The data demonstrate that night-migrating birds are driven by autonomous circadian clocks entrained by sunset cues. This timekeeping system is probably the key factor in the overall control of nocturnal songbird migration.

  3. Returning to sports after a back injury

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000518.htm Returning to sports after a back injury To use the sharing ... Back pain - returning to sports Which Type of Sport is Best? In deciding when and if to ...

  4. Returns to Tenure or Seniority?

    DEFF Research Database (Denmark)

    Buhai, Ioan Sebastian; Portela, Miguel; Teulings, Coen

      This study documents two empirical regularities, using data for Denmark and Portugal. First, workers who are hired last, are the first to leave the firm (Last In, First Out; LIFO). Second, workers' wages rise with seniority (= a Worker's tenure relative to the tenure of her colleagues). We seek...... at the moment of separation). The LIFO rule provides a stronger bargaining position for senior workers, leading to a return to seniority in wages. Efficiency in hiring requires the workers' .bargaining power to be in line with their share in the cost of specific investment. Then, the LIFO rule is a way...

  5. Network migration for printers

    CERN Multimedia

    2016-01-01

    Further to the recent General Purpose (office) Network reorganisation (as announced in the Bulletin - see here), please note that the majority of print devices will be automatically migrated to the new network IP address range on Tuesday 27 September.   This change should be transparent for these devices and therefore end-users, provided you have installed the printers from the Print Service website. A small number of devices will require manual intervention from the Printer Support team in order to migrate correctly. These devices will not change their IP address until the manual intervention, which will be carried out before Monday 3rd October. However, if you have mistakenly connected directly to the printer’s IP address, then your printing will be affected – please uninstall the printer (for help, see: KB3785), and re-install it from the Print Service website (or follow instructions for visitor machines). Please do this as soon as possible in order to avoid printing issues, t...

  6. Globalization of leptospirosis through travel and migration.

    Science.gov (United States)

    Bandara, Medhani; Ananda, Mahesha; Wickramage, Kolitha; Berger, Elisabeth; Agampodi, Suneth

    2014-08-12

    Leptospirosis remains the most widespread zoonotic disease in the world, commonly found in tropical or temperate climates. While previous studies have offered insight into intra-national and intra-regional transmission, few have analyzed transmission across international borders. Our review aimed at examining the impact of human travel and migration on the re-emergence of Leptospirosis. Results suggest that alongside regional environmental and occupational exposure, international travel now constitute a major independent risk factor for disease acquisition. Contribution of travel associated leptospirosis to total caseload is as high as 41.7% in some countries. In countries where longitudinal data is available, a clear increase of proportion of travel-associated leptospirosis over the time is noted. Reporting patterns is clearly showing a gross underestimation of this disease due to lack of diagnostic facilities. The rise in global travel and eco-tourism has led to dramatic changes in the epidemiology of Leptospirosis. We explore the obstacles to prevention, screening and diagnosis of Leptopirosis in health systems of endemic countries and of the returning migrant or traveler. We highlight the need for developing guidelines and preventive strategies of Leptospirosis related to travel and migration, including enhancing awareness of the disease among health professionals in high-income countries.

  7. Common Factors in International Bond Returns

    NARCIS (Netherlands)

    Driessen, J.J.A.G.; Melenberg, B.; Nijman, T.E.

    2000-01-01

    In this paper we estimate and interpret the factors that jointly determine bond returns of different maturities in the US, Germany and Japan.We analyze both currency-hedged and unhedged bond returns.For currency-hedged bond returns, we find that five factors explain 96.5% of the variation of bond

  8. Foreign currency returns and systematic risks

    NARCIS (Netherlands)

    Galsband, V.; Nitschka, T.

    2015-01-01

    We apply an empirical approximation of the intertemporal capital asset pricing model (ICAPM) to show that cross-sectional dispersion in currency returns can be rationalized by differences in currency excess returns' sensitivities to the market return's cash-flow news component. This finding echoes

  9. [Ministerial Conference on Migration and Urbanization in West Africa: declaration].

    Science.gov (United States)

    1999-12-01

    This declaration made by the participants of the Ministerial Conference on Migration and Urbanization in Western Africa, held in Bamako during November 5, 1999, commits the countries of the region to do the following: follow the urbanization process in an effort to make African cities hubs of development and social progress; improve the geographic distribution of populations; bring economic development to mid-sized cities; implement rural development projects and programs, especially in the least advantaged zones; manage urban constraints; define new pathways and coordinated approaches; implement measures which account for those who are newly migrating, such as women and young people; minimize administrative hurdles associated with the return and reintegration of migrants; provide those bodies responsible for urbanization and migration concerns with the communication tools they require; take the necessary measures to facilitate migrants¿ stays and inform potential migrants about the conditions of such stay in host countries; adapt laws to conform with the charters of subregional organizations; consider migration concerns at the commission level; and implement clear, explicit migration policies. Recommendations are offered to the Permanent Interstate Committee Against Drought in the Sahel (CILSS) as well as to all subregional organizations. It is hoped that international organizations and partner agencies in development will support countries¿ efforts.

  10. Modeling of SAR returns from a red pine stand

    Science.gov (United States)

    Lang, R. H.; Kilic, O.; Chauhan, N. S.; Ranson, J.

    1992-01-01

    Bright P-band radar returns from red pine forests have been observed on synthetic aperture radar (SAR) images in Bangor, Maine. A plot of red pine trees was selected for the characterization and modeling to understand the cause of the high P-band returns. The red pine stand under study consisted of mature trees. Diameter at breast height (DBH) measurements were made to determine stand density as a function of tree diameter. Soil moisture and bulk density measurements were taken along with ground rough surface profiles. Detailed biomass measurements of the needles, shoots, branches, and trunks were also taken. These site statistics have been used in a distorted Born approximation model of the forest. Computations indicate that the direct-reflected or the double-bounce contributions from the ground are responsible for the high observed P-band returns for HH polarization.

  11. Health Status and Experience of the Migrant Workers Returned from Spain to Colombia: A Qualitative Approach.

    Science.gov (United States)

    Zapata-Villa, Carolina; Agudelo-Suárez, Andrés A; Cardona-Arango, Doris; Ronda-Pérez, Elena

    2017-12-14

    This study aims to understand the migratory experience and the employment, work and health conditions of the returned migrants from Spain to Colombia. A qualitative study was conducted by means of 23 semi-structured interviews with Colombian returned migrant workers. Qualitative narrative content analysis was performed using Atlas.Ti software. Main findings are represented by nine categories emerged from the participants' discourses: (1) impact of the economic crisis on work and employment conditions in Spain, (2) economic crisis and return, (3) characteristics of returnees, (4) perception of the returnees about Colombia, (5) the role of social support networks, (6) employment and working conditions in Colombia, (7) health and wellbeing, (8) future plans and expectations, (9) the experience of being immigrant. Adjustment difficulties in participants are evidenced by the return migration process and the conditions of the social, political and economic system in Colombia. Return migration represents the reconfiguration of personal and working lives of this population. This situation requires the development of global policies and strategies in public health to facilitate the adaptation of these people.

  12. Nordic Migration and Integration Research

    OpenAIRE

    Pyrhönen, Niko; Martikainen, Tuomas; Leinonen, Johanna

    2017-01-01

    EXECUTIVE SUMMARY Migration and integration are currently highly contentious topics in political, public and scientific arenas, and will remain so in the near future. However, many common migration-related prejudices and inefficien¬cies in the integration of the migrant population are due to the lack of sound, tested and accessible scientific research. Therefore, the study of migration – by developing basic research and by properly resourcing novel methodological approaches and interventions ...

  13. The challenges of managing migration

    Energy Technology Data Exchange (ETDEWEB)

    Tacoli, Cecilia

    2005-10-15

    Migration and urbanisation are driven by economic growth and social change, but also by deepening inequalities. Managing migration should not be equated with curbing it, as this inevitably reduces migrants' rights. But managing population movement whilst respecting the rights of migrants and nonmigrants, supporting the contribution of migration to poverty reduction and economic growth in sending and receiving areas and reducing the human and material costs of movement means that fundamental challenges need to be addressed.

  14. Croatia’s Migration Potential – Micro-Analytic Aspects

    Directory of Open Access Journals (Sweden)

    Saša Božić

    2005-06-01

    Full Text Available The authors set criteria for the selection of a model for measuring migration potential; they select and apply such a model to Croatia and determine the practical and scientific relevance of the Croatian case, especially its significance for the improvement of the chosen model. The authors concentrate on the application of Heinz Fassmann’s and Christiane Hintermann’s micro-analytic model for the estimation of East-Central Europe’s migration potential. After applying this model, they estimate Croatia’s total migration potential at 12.5%, i.e. 460,000 persons older than fourteen. The probable migration potential is estimated at 2.5%, i.e. 92,000 and the real migration potential at 0.4% of the population above fourteen, i.e. 14,700 persons. In Croatian case as well, the younger population (which can still utilise its labour capacity, as well as unemployed, unmarried and highly educated persons, are more likely to consider emigration. The data show also that the regions with the lowest share in GNP have the highest percentage of potential migrants and not the regions which are geographically the closest to potential immigration countries. The authors stress the necessity to integrate migration potential research models. The explanatory assumptions of migration potential research models, based on place utility and subjective expected utility, often overlap when used to interpret the data. Furthermore, the Croatian case shows that personal migration experience and the analytical mezzo level must be considered in order to gain an understanding of the creation of migration preferences.

  15. Europe in Movement: Migration from and into Eastern and Central Europe

    Directory of Open Access Journals (Sweden)

    Marek Okólski

    2009-01-01

    Full Text Available Two historical events have had a fundamental importance in shaping the new migration trends in Eastern and Central Europe (ECE: the collapse of the Soviet block and the region’s return to Europe, when the first eight countries became full members of the European Unionon 1 May 2004 as a point of inflection. Before 1990, and for several decades, international migration was contained by the totalitarian regimes of the ECE. Based on this scenario, the study describes the different kinds of migration movements that have taken place inthe region since 1989; it analyses migration processes from and into the ECE following its incorporation into the European Union, as well as examining the possible causes for the size, dynamics and geographic direction of the migration flows that took place between EU-8 and EU-15, since the EU carried out its eastward enlargement.

  16. Rural migration in Nevada: Lincoln County. Phase 1, 1992--1993

    Energy Technology Data Exchange (ETDEWEB)

    Soden, D.L.; Carns, D.E.; Mosser, D.; Conary, J.S.; Ansell, J.P.

    1993-12-31

    The principal objective of this project was to develop insight into the scope of migration of working age Nevadans out of their county of birth; including the collection of data on their skill levels, desire to out or in-migrate, interactions between families of migratory persons, and the impact that the proposed high-level nuclear waste repository at Yucca mountain might have on their individual, and collective, decisions to migrate and return. The initial phase of this project reported here was conducted in 1992 and 1993 in Lincoln County, Nevada, one of the counties designated as ``affected`` by the proposed repository program. The findings suggest that a serious out-migration problem exists in Lincoln County, and that the Yucca mountain project will likely affect decisions relating to migration patterns in the future.

  17. Nurse migration from India: a literature review.

    Science.gov (United States)

    Garner, Shelby L; Conroy, Shelley F; Bader, Susan Gerding

    2015-12-01

    A profound nursing shortage exists in India where nurses are increasingly outmigrating to practice nursing in surrounding countries and abroad. This is important globally because countries with the lowest nursing and healthcare workforce capacities have the poorest health outcomes. This review sought to synthesize and unify the evidence about nurse migration from India and includes a look at nurse retention within India. A comprehensive literature review was performed to synthesize and unify both qualitative and quantitative research. Bibliographic databases searched included CINAHL, MEDLINE, PsycINFO, and EconLit using associated keywords for empirical and descriptive literature published between January 2004 and May 2014. Hand searches of the Nursing Journal of India from 2004 to February 2014 and the Journal of Nursing Research Society of India from its inception in 2007-February 2014 were also completed. 29 studies were selected and analyzed for the review. Data were appraised for quality; reduced through sub-categorization; extracted; and coded into a framework. Thematic interpretation occurred through comparing and contrasting performed by multiple reviewers. Findings included an exponential growth in nurse recruitment efforts, nurse migration, and a concomitant growth in educational institutions within India with regional variations in nurse migration patterns. Decision-making factors for migration were based on working conditions, salience of family, and the desire for knowledge, skill, technology, adventure and personal enrichment. Challenges associated with migration included questionable recruiting practices, differing scopes of practice encountered after migration and experiences of racism and cultural differences. A shift toward a positive transformation of nursing status in India has resulted in an increased respect for individual nurses and the profession of nursing. This was attributed to the increased globalization of nursing. Results from this

  18. Stock Returns and Risk: Evidence from Quantile

    Directory of Open Access Journals (Sweden)

    Thomas C. Chiang

    2012-12-01

    Full Text Available This paper employs weighted least squares to examine the risk-return relation by applying high-frequency data from four major stock indexes in the US market and finds some evidence in favor of a positive relation between the mean of the excess returns and expected risk. However, by using quantile regressions, we find that the risk-return relation moves from negative to positive as the returns’ quantile increases. A positive risk-return relation is valid only in the upper quantiles. The evidence also suggests that intraday skewness plays a dominant role in explaining the variations of excess returns.

  19. Contradictions of international migration in terms of political economy

    Directory of Open Access Journals (Sweden)

    Josifidis Kosta

    2016-01-01

    political economy approach is faced with the tension between the two approaches. The first proposed regulation and workforce management at the supranational level. The other remains in the framework of “methodological nationalism”: the appropriate starting point is the national state. Given the fact that structural inequalities should be recognized at a global level, and that processes of migration show that there is a certain hierarchical global flow in the context of the dynamics of workforce, the first approach proves to be inadequate. In other words, the second approach could not articulate the relevant tendencies. Accordingly, the political economy approach that intends to include complex determination regarding the migration should integrate the national trends in the supranational framework. But, proper research should take into account that globalization and its complex order consist of a number of interventions and interferences. This means that the aforementioned approach must develop sufficiently complex methodology in order to articulate its selected subject.

  20. A study on relationship between the return of value/growth portfolio and market return: Evidence from Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Monireh Mashhadi Ramezanali

    2014-07-01

    Full Text Available This study examines the relationship between the returns of two value and growth portfolios and the return of market on 15 selected firms on Tehran Stock Exchange over the period 2008-2011. The study divides the firms into two groups in terms of the ratios of price on earning as well as price on book value into two groups of value and growth portfolios. Using some regression analysis, the study has determined a positive and meaningful relationship between value portfolio and market return when the market is on the upside but this relationship is not meaningful during the bear session. The results indicate that during the bull sessions, value portfolios provide better investment opportunities than growth ones do.

  1. Countering inbreeding with migration 1. Migration from unrelated ...

    African Journals Online (AJOL)

    Ret:ieved 6 Octoher 1991; ut:cepted I8 Mur- 1995. The eff'ect of migration on inbreeding is moclelled fbr small populations with immigrants from a large unrelated population. Different migration rates and numbers fbr the two sexes are assumed, and a general recursion equation for inbreeding progress derived, which can ...

  2. Labour migration and rural transformation in Nigeria.

    Science.gov (United States)

    Onyeonoru, I P

    1994-06-01

    The trends in rural-urban migration in Nigeria responded to changes in political and socioeconomic developments which occurred during the 1980s. Since the 1980s, rural-urban migration trends were rapidly reversed, and migrants returned to rural areas. In 1981, government revenues from oil declined. The oil production and price declines between 1980 and 1986 resulted in a foreign exchange crisis. Import restrictions were imposed, and stabilization measures resulted in scarcities of raw materials and spare parts and declines in industrial capacity. About 50% of import substitution factories went bankrupt. Between 1981 and 1983, about one million workers were estimated to have been laid off, of which 55,000 were federal and state employees. Other estimates indicated one million laid off just in the industrial sector. The government reinforced this urban-rural movement by emphasizing increased food production. In 1992, government wages were increased in order to offset high inflation. In 1986 and 1992, State and Local Government Areas were established as political entities tied to grassroots development; local offices were situated in greater proximity to local populations. In 1986, the objective was to provide infrastructure, promote production, and organize rural areas for development. Several community banks devoted to rural areas were established. Development programs for rural women were initiated. Federal revenue allocations to rural areas increased from 10% to 15%. Inducements were given to attract private formal and informal commerce and industry. The result was less than expected. Obstacles to rural development included the absence of an effective and integrated approach, inadequate funding, and corruption. Provision of good roads and schools did meet objectives and may have induced out-migration. Delays in provision of entitlements exacerbated the ability of return migrants to establish new economic activity. The new political divisions did not conform to

  3. Improved intake design for downstream migrating fish at hydropower plants

    International Nuclear Information System (INIS)

    Mih, W.C.

    1991-01-01

    This paper reports on hydroelectric power projects on the Columbia River which provided low-cost electricity to the Pacific Northwest. However, they are detrimental to anadromous fisheries resources. Anadromous fish are migratory. They begin their life in shallow mountain streams. After several months, they migrate to the ocean, where the fish grow to maturity before their return migration. Remarkably, most anadromous fish return to spawn in their natal streams. At dams, the upstream migration of grown salmon and steelhead is accomplished through fishways. The downstream migration of juveniles remains a serious problem. Juvenile fish follow the water flow during their sea-ward migration. When passing through a turbine, fish can be severely injured due to the sudden pressure drop, high velocity shear zones, and rotating turbine blades. Stunned fish that survive the gauntlet of the turbine are easy prey for sea gulls and squawfish in the tailrace of the powerhouse. Fish mortality per turbine passage is estimated at 15 percent. With nine hydropower projected on the main steam of the Columbia River, their combined mortality is very serious. The historical Columbia River anadromous run of about 12 million fish has declined to 2.5 million in recent years. Modern high-output hydraulic turbines are designed to be placed at a lower elevation to minimize cavitation damage to turbine blades. The modern design trend of deep intake submergence has caused parallel and unsteady vortex flow patterns in the forebay, resulting in a decrease in the guiding efficiency of the screens, such as at Bonneville Second Powerhouse and at Rocky Reach Project

  4. 76 FR 22611 - Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic...

    Science.gov (United States)

    2011-04-22

    ... Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic Media... Register on Wednesday, March 30, 2011 (76 FR 17521) providing guidance to specified tax return preparers who prepare and file individual income tax returns using magnetic media pursuant to section 6011(e)(3...

  5. Migration and regional inequality

    DEFF Research Database (Denmark)

    Peng, Lianqing; Swider, Sarah

    2017-01-01

    Scholars studying economic inequality in China have maintained that regional inequality and economic divergence across provinces have steadily increased over the past 30 years. New studies have shown that this trend is a statistical aberration; calculations show that instead of quickly and sharply...... rising, regional inequality has actually decreased, and most recently, remained stable. Our study suggests that China’s unique migratory regime is crucial to understanding these findings. We conduct a counterfactual simulation to demonstrate how migration and remittances have mitigated income inequality...... across provinces in order to show that without these processes, we would have seen more of a rise in interprovincial income inequality. We conclude by arguing that inequality in China is still increasing, but it is changing and becoming less place-based. As regional inequality decreases, there are signs...

  6. Tracking migrating birds

    DEFF Research Database (Denmark)

    Willemoes, Mikkel

    habitats with those in rural habitats. Some species have decreased the frequency of migrants and migration distance in urban environments, and others have not. The other manuscript describes the small scale movements of three different Palaearctic migrants during winter in Africa in a farmland habitat....... In another species, environmental conditions are not a good predictor of movements, and possibly effects of timing constraints or food type play a role. Two manuscripts focus on the effects of human-induced habitat alterations on migratory behaviour. One compares the movements of partial migrants in urban...... and a forest reserve. In the degraded habitat all species used more space, although the consequence on bird density is less clear. Two manuscripts relate the migratory movements of a long-distance migrant with models of navigation. One compares model predictions obtained by simulation with actual movements...

  7. Making Migration Meaningful

    DEFF Research Database (Denmark)

    Benwell, Ann Fenger

    2013-01-01

    a way to escape family patriarchy and conformity, and can contribute to loss, hardship, and uncertainty for family members left behind. Further, mobility provides opportunities and a means to escape the stigma of ‘laziness’ culturally associated with poverty and immobility. Postsocialist separation has...... of absence by migrant family members, as both men and women are culturally permitted to be separate from their families. Migration is understood to contribute to prosperity, and separations contribute to generate growth and hishig (good fortune) for the good of the family. However, such mobility is also......Mongolia has experienced two decades since the demise of the Soviet Union and has implemented strategies to strengthen its economy and its democratic practices. Transitions from being a nomadic society to a Soviet satellite state and onwards to liberal democracy have greatly impacted family life...

  8. Nightly Test system migration

    CERN Document Server

    Win-Lime, Kevin

    2013-01-01

    The summer student program allows students to participate to the Cern adventure. They can follow several interesting lectures about particle science and participate to the experiment work. As a summer student, I had worked for LHCb experiment. LHCb uses a lot of software to analyze its data. All this software is organized in packages and projects. They are built and tested during the night using an automated system and the results are displayed on a web interface. Actually, LHCb is changing this system. It is looking for a replacement candidate. So I was charged to unify some internal interfaces to permit a swift migration. In this document, I will describe shortly the system used by LHCb, then I will explain what I have done in detail.

  9. Lunar lander and return propulsion system trade study

    Science.gov (United States)

    Hurlbert, Eric A.; Moreland, Robert; Sanders, Gerald B.; Robertson, Edward A.; Amidei, David; Mulholland, John

    1993-01-01

    This trade study was initiated at NASA/JSC in May 1992 to develop and evaluate main propulsion system alternatives to the reference First Lunar Outpost (FLO) lander and return-stage transportation system concept. Thirteen alternative configurations were developed to explore the impacts of various combinations of return stage propellants, using either pressure or pump-fed propulsion systems and various staging options. Besides two-stage vehicle concepts, the merits of single-stage and stage-and-a-half options were also assessed in combination with high-performance liquid oxygen and liquid hydrogen propellants. Configurations using an integrated modular cryogenic engine were developed to assess potential improvements in packaging efficiency, mass performance, and system reliability compared to non-modular cryogenic designs. The selection process to evaluate the various designs was the analytic hierarchy process. The trade study showed that a pressure-fed MMH/N2O4 return stage and RL10-based lander stage is the best option for a 1999 launch. While results of this study are tailored to FLO needs, the design date, criteria, and selection methodology are applicable to the design of other crewed lunar landing and return vehicles.

  10. Migration Regulation Contagion

    DEFF Research Database (Denmark)

    Brücker, Herbert; Schröder, Philipp J.H.

    This paper examines the political economy of a selective immigration policy in a model with incomplete information on the characteristics of migrants. We address two questions: First, how does a selective immigration policy affect the number of immigrants which is admitted by the receiving countr...

  11. Application of Markowitz model in analysing risk and return a case study of BSE stock

    Directory of Open Access Journals (Sweden)

    Manas Pandey

    2012-03-01

    Full Text Available In this paper the optimal portfolio formation using real life data subject to two different constraint sets is attempted. It is a theoretical framework for the analysis of risk return choices. Decisions are based on the concept of efficient portfolios. Markowitz portfolio analysis gives as output an efficient frontier on which each portfolio is the highest return earning portfolio for a specified level of risk. The investors can reduce their risks and can maximize their return from the investment, The Markowitz portfolio selections were obtained by solving the portfolio optimization problems to get maximum total returns, constrained by minimum allowable risk level. Investors can get lot of information knowledge about how to invest when to invest and why to invest in the particular portfolio. It basically calculates the standard deviation and returns for each of the feasible portfolios and identifies the efficient frontier, the boundary of the feasible portfolios of increasing returns

  12. Challenged by migration: Europe's options

    NARCIS (Netherlands)

    Constant, Amelie F.; Zimmermann, Klaus F.

    2017-01-01

    This paper examines the migration and labour mobility in the European Union and elaborates on their importance for the existence of the EU. Against all measures of success, the current public debate seems to suggest that the political consensus that migration is beneficial is broken. This comes with

  13. Radionuclide migration studies in soil

    International Nuclear Information System (INIS)

    Marumo, J.T.

    1989-01-01

    In this work a brief description about retention and migration parameters of radionuclides in soil, including main methods to determine the distribution coefficient (K) are given. Some of several factors that can act on the migration are also mentioned. (author) [pt

  14. South-South Migration and Remittances

    OpenAIRE

    Ratha, Dilip; Shaw, William

    2007-01-01

    South-South Migration and Remittances reports on preliminary results from an ongoing effort to improve data on bilateral migration stocks. It sets out some working hypotheses on the determinants and socioeconomic implications of South-South migration. Contrary to popular perception that migration is mostly a South-North phenomenon, South-South migration is large. Available data from nation...

  15. Migration and income transfers in the presence of labor quality externalities

    NARCIS (Netherlands)

    Huizinga, H.P.

    1994-01-01

    In this paper, a worker's productivity is assumed to depend on his own quality and on the average quality of other workers in the same country. The external effects associated with worker quality give rise to increasing returns to average worker quality. As a result, free migration generally reduces

  16. Measuring International Migration in Azerbaijan

    Directory of Open Access Journals (Sweden)

    Serhat Yüksel

    2018-01-01

    Full Text Available International migration significantly affects economic, social, cultural, and political factors of the country. Owing to this situation, it can be said that the reasons of international migration should be analyzed in order to control this problem. The purpose of this study is to determine the influencing factors of international migration in Azerbaijan. In this scope, annual data of 11 explanatory variables for the period of 1995–2015 was analyzed via Multivariate Adaptive Regression Splines (MARS method. According to the results of this analysis, it was identified that people prefer to move other countries in case of high unemployment rates. In addition, the results of the study show that population growth and high mortality rate increases the migration level. While considering these results, it was recommended that Azerbaijan should focus on these aspects to control international migration problem.

  17. Wages, Welfare Benefits and Migration.

    Science.gov (United States)

    Kennan, John; Walker, James R

    2010-05-01

    Differences in economic opportunities give rise to strong migration incentives, across regions within countries, and across countries. In this paper we focus on responses to differences in welfare benefits across States. We apply the model developed in Kennan and Walker (2008), which emphasizes that migration decisions are often reversed, and that many alternative locations must be considered. We model individual decisions to migrate as a job search problem. A worker starts the life-cycle in some home location and must determine the optimal sequence of moves before settling down. The model is sparsely parameterized. We estimate the model using data from the National Longitudinal Survey of Youth (1979). Our main finding is that income differences do help explain the migration decisions of young welfare-eligible women, but large differences in benefit levels provide surprisingly weak migration incentives.

  18. Migrating and herniating hydatid cysts

    International Nuclear Information System (INIS)

    Koc, Zafer; Ezer, Ali

    2008-01-01

    Objective: To present the prevalence and imaging findings of patients with hydatid disease (HD) showing features of migration or herniation of the hydatid cysts (HCs) and underline the clinical significance of this condition. Materials and methods: Between May 2003 and June 2006, 212 patients with HD were diagnosed by abdomen and/or thorax CT, searched for migrating or herniating HC. Imaging findings of 7 patients (5 women, 2 men with an age range of 19-63 years; mean ± S.D., 44 ± 19 years) with HD showing transdiaphragmatic migration (6 subjects) or femoral herniation (1 subject) were evaluated. Diagnosis of all the patients were established by pathologic examination and migration or herniation was confirmed by surgery in all patients. Results: Liver HD were identified in 169 (79.7%) of 212 patients with HD. Transdiaphragmatic migration of HCs were identified in 6 (3.5%) of the 169 patients with liver HD. In one patient, femoral herniation of the retroperitoneal HC into the proximal anterior thigh was identified. All of these seven patients exhibiting migration or herniation of HCs had active HCs including 'daughter cysts'. Two patients had previous surgery because of liver HD and any supradiaphragmatic lesion was not noted before operation. Findings of migration or herniation were confirmed by surgery. Conclusion: Active HCs may show migration or herniation due to pressure difference between the anatomic cavities, and in some of the patients, by contribution of gravity. Previous surgery may be a complementary factor for migration as seen in two of our patients. The possibility of migration or herniation in patients with HD should be considered before surgery

  19. Current Migration Movements in Europe

    Directory of Open Access Journals (Sweden)

    Jelena Zlatković Winter

    2004-09-01

    Full Text Available After a brief historical review of migrations in Europe, the paper focuses on current migration trends and their consequences. At the end of the 1950s, Western Europe began to recruit labour from several Mediterranean countries – Italy, Spain, Portugal and former Yugoslavia, and later from Morocco, Algeria, Tunisia and Turkey. Some countries, such as France, Great Britain and the Netherlands, recruited also workers from their former colonies. In 1970 Germany had the highest absolute number of foreigners, followed by France, and then Switzerland and Belgium. The total number of immigrants in Western Europe was twelve million. During the 1970s mass recruitment of foreign workers was abandoned, and only the arrival of their family members was permitted, which led to family reunification in the countries of employment. Europe closed its borders, with the result that clandestine migration increased. The year 1989 was a turning point in the history of international migrations. The political changes in Central and Eastern Europe brought about mass migration to the West, which culminated in the so-called “mass movement of 1989–1990”. The arrival of ethnic Germans in Germany, migration inside and outside of the territory of the former Soviet Union, an increase in the number of asylum seekers and displaced persons, due to armed conflicts, are – according to the author – the main traits of current migration. The main part of the paper discusses the causes and effects of this mass wave, as well as trends in labour migration, which is still present. The second part of the paper, after presenting a typology of migrations, deals with the complex processes that brought about the formation of new communities and led to the phenomenon of new ethnic minorities and to corresponding migration policies in Western European countries that had to address these issues.

  20. A novel molecular index for secondary oil migration distance.

    Science.gov (United States)

    Zhang, Liuping; Li, Maowen; Wang, Yang; Yin, Qing-Zhu; Zhang, Wenzheng

    2013-01-01

    Determining oil migration distances from source rocks to reservoirs can greatly help in the search for new petroleum accumulations. Concentrations and ratios of polar organic compounds are known to change due to preferential sorption of these compounds in migrating oils onto immobile mineral surfaces. However, these compounds cannot be directly used as proxies for oil migration distances because of the influence of source variability. Here we show that for each source facies, the ratio of the concentration of a select polar organic compound to its initial concentration at a reference point is independent of source variability and correlates solely with migration distance from source rock to reservoir. Case studies serve to demonstrate that this new index provides a valid solution for determining source-reservoir distance and could lead to many applications in fundamental and applied petroleum geoscience studies.

  1. [Return scholarship of the Universidad Peruana Cayetano Heredia].

    Science.gov (United States)

    Guerra, Humberto

    2010-09-01

    Developing countries suffer from brain drain for many decades. Industrialized countries have raised their barriers against immigrants, but have created mechanisms to attract foreign professionals, with aggressive policies to capture talents, in an effort to increase their competitiveness. To mitigate the effects of the migration of scientists, the Universidad Peruana Cayetano Heredia has created its own "return scholarship" about 12 years ago, and has repatriated 12 scientists through it. The funds invested in attracting the scholars total U.S. $333,540.00 and they have secured U.S. $9,249,828.42 in research funds during the same period, a figure over 27 times higher. They have published 8 articles in national journals, 68 internationally, and trained 29 undergraduate and 20 graduate students as Thesis Tutors. Other universities and institutions of our countries can emulate this successful experience, which is still evolving.

  2. Stage IV in electrical resistivity return to alpha-iron

    International Nuclear Information System (INIS)

    Poltavtseva, V.P.

    2004-01-01

    Full text: In compliance with the model of two interstitial atoms, in returning the electrical resistivity increment, the stage IV, related to migration of mono vacancies, should exist. Unfortunately, for alpha-iron there is no any reliable proof of existence of the stage IV (450-630 K) up to now. As a rule, the annealing stages revealed within this temperature range are considered as related to impurity effects. This paper is aimed at detection of the stage IV in returning the electrical resistivity increment in alpha-iron by means of irradiation of the materials differing in purity degree (99.99 and 99.8 %) by 30 MeV protons capable to create large amount of point defects and small clusters in BCC metals. By author opinion, it will make it possible to reach the radiation defect/vacancy concentrations comparable with contents of impurities (C and N) and, thus, to obtain an information about their migration. As a result of irradiation by protons at 270 K up to the fluence comprising 2.3·10 21 m -2 (0.001 dpa), the following has been found: - an increase in the electrical resistivity at 330 K is 0.84 and 0.61 nΩ·m for the alpha-iron purity degree 99.99 and 99.8 % respectively; - in the 99.99 % purity degree alpha-iron the process of electrical resistivity restoration comes to an end completely at 563 K, whereas in alpha-iron with larger content of impurity - at nearly 600 K; - in the 99.99% purity degree alpha iron electrical resistivity return spectrum a single wide peak centered at 445 K and two smeared peaks below 400 and higher than 490 K are revealed. As the impurity content increases, the 464 K peak changes the 445 K peak, which is about twice lower. Besides, a peak at 377 K occurs, and the peak at a temperature higher than 500 K, in contrast to the 99.99 % purity degree alpha-iron, has a point of inflection at 590 K. On a base of the data obtained, one may conclude that the stage centered around 445 K is of intrinsic nature, and the 99.99 % purity degree

  3. Lines of evidence for environmentally driven human migration

    Science.gov (United States)

    Davis, K. F.; D'Odorico, P.

    2012-12-01

    International human migration is an important mechanism that affects, and is affected by, various human and natural systems. With the number of people living outside their countries of origin currently estimated at 214 million people and projected to potentially reach more than 400 million people by mid-century, the topic of international human movements presents possible advantages and pitfalls for both sending and receiving countries on multiple fronts (e.g. economic, environmental, political and cultural). Understanding how human migration interacts with human and natural systems is therefore essential in realizing a sustainable and balanced future. While the study of international migration has historically been motivated largely by economic and political interests, the issue of environmentally induced migration has become increasingly important in light of a rapidly changing climate in conjunction with increasing population pressure on many important resources. Particularly in terms of theoretical and conceptual discussions, environmentally induced human migration has been receiving increased attention in the literature. To date, few studies - many of which focus on internal (intra-national) or regional migration - have attempted to quantify the interactions of human migration and the environment, with little attention paid to the global scale as a result of varying regional factors and lack of sufficient data. Recently available global bilateral migration datasets have been developed that allow for a more comprehensive understanding of human movements between all countries. With these datasets, we seek to elucidate environmental drivers of human migration over the past half-century using a multi-pronged approach. First, using a recently developed universal radiation model, we examine human movements based solely on global population distribution. Next, by comparison of migration movements with selected economic, environmental and human welfare indicators, we

  4. Understanding gendered aspects of migration aspiration and motives of university students by multivariate statistical methods

    Directory of Open Access Journals (Sweden)

    Đula Borozan

    2014-03-01

    Full Text Available The paper deals with the application of multivariate analysis of variance and logistic regression in measuring, explaining and evaluating (i gender differences in expressing migration aspirations, and (ii a gender effect on migration motivation of university students in Croatia. The results supported the thesis that migration is a complex gendering process that assumes subjective assessment of the whole set of interrelated motives. According to logistic regression, gender is a significant predictor of migration aspirations among the selected demographic and socio-economic variables. A multivariate analysis of variance showed that gender and migration aspirations in interaction matter when it comes to migration motives, particularly related to the perceived importance of social networks. Females, and especially those who aspire to migrate, assessed these motives as more important than males.

  5. The Determinants of Actual Migration and the Role of Wages and Unemployment in Albania: an Empirical Analysis

    Directory of Open Access Journals (Sweden)

    Cristina Cattaneo

    2008-06-01

    Full Text Available The paper explores the determinants of internal migration in Albania, adopting the Harris-Todaro approach to migration: an internal migration function is estimated using district wage and unemployment rate differentials. The aggregate level wages and unemployment, included in the migration equation, are retrieved from a first stage wage and unemployment equations, estimated controlling for personal characteristics. Moreover, in order to test the predictions of the human capital model of migration, the difference between migrants and non-migrants is emphasized in the estimation. The data source is the "Living Standard Measurement Survey for Albania" (2002, undertaken by the national Institute of Statistics and the World Bank jointly. The results reveal that both wage and unemployment differentials are important determinants of the propensity to migrate in Albania. This conclusion is further emphasized by noting that migrants gain substantially in terms of higher returns to individual characteristics after emigration.

  6. The Return to Schooling in Structural Dynamic Models: A Survey

    OpenAIRE

    Christian Belzil

    2007-01-01

    Working paper du GATE 2006-09; This papers contains a survey of the recent literature devoted to the returns to schooling within a dynamic structural framework. I present a historical perspective on the evolution of the literature, from early static models set in a selectivity framework (Willis and Rosen, 1979) to the recent literature, stimulated by Keane and Wolpin (1997), and which uses stochastic dynamic programming techniques. After reviewing the literature thoroughly, I compare the stru...

  7. NNDC database migration project

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, Thomas W; Dunford, Charles L [U.S. Department of Energy, Brookhaven Science Associates (United States)

    2004-03-01

    NNDC Database Migration was necessary to replace obsolete hardware and software, to be compatible with the industry standard in relational databases (mature software, large base of supporting software for administration and dissemination and replication and synchronization tools) and to improve the user access in terms of interface and speed. The Relational Database Management System (RDBMS) consists of a Sybase Adaptive Server Enterprise (ASE), which is relatively easy to move between different RDB systems (e.g., MySQL, MS SQL-Server, or MS Access), the Structured Query Language (SQL) and administrative tools written in Java. Linux or UNIX platforms can be used. The existing ENSDF datasets are often VERY large and will need to be reworked and both the CRP (adopted) and CRP (Budapest) datasets give elemental cross sections (not relative I{gamma}) in the RI field (so it is not immediately obvious which of the old values has been changed). But primary and secondary intensities are now available on the same scale. The intensity normalization has been done for us. We will gain access to a large volume of data from Budapest and some of those gamma-ray intensity and energy data will be superior to what we already have.

  8. Radionuclide migration in soils

    Energy Technology Data Exchange (ETDEWEB)

    Demir, M [Ingenieurgesellschaft Bonnenberg und Drescher, Juelich (Germany, F.R.)

    1979-01-01

    Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10/sup -3/) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10/sup -2/) and one tenth (10/sup -1/) that of T respectively.

  9. Radionuclide migration in soils

    International Nuclear Information System (INIS)

    Demir, M.

    1979-01-01

    Unplanned releases from a nuclear installation - e.g., leakage from a storage tank or other incident - can result in the escape of contaminants such as U, Pu, Cs, Sr, T etc. Nuclide transport through the ground is governed by characteristics of the subsurface hydrology and the specific nuclides under consideration. Unsaturated soil layers result in a transport rate so low as to negligible. Radionuclides reaching the ground water are assumed to endanger human life because of potential uncontrolled ingestion. The most dangerous nuclides are long-lived and not absorbed, or very poorly absorbed, in the soil. During migration of nuclides through saturated soil layers, the concentration can be reduced by dilution. Preliminary results indicate that tritium is spread with ground water velocity. Its concentration can be reduced only by diffusion, dispersion and radioactive decay. Alpha-emitters are strongly retained velocities of alpha-emitters are approximately one thousandth (10 -3 ) that of T. Transport velocities of Cs and Sr are approximately one hundreth (10 -2 ) and one tenth (10 -1 ) that of T respectively. (orig./HP) [de

  10. Psychosocial Aspects of Migration

    Directory of Open Access Journals (Sweden)

    Ayla Tuzcu

    2014-02-01

    Full Text Available The incident of migration that occurs as a result of the mobility of individuals between various regions and is considered a social change process brings along various factors. Among these factors, the most important one is the culture of the new society where the immigrant begins to live and the process of adaptation with this culture. Individuals from different cultures are required to live together, cope with differences and overcome the difficulties. The process of adaptation to the new lifestyle might cause the individual to have some feelings such as loneliness, socially isolation, being alienated, being regretful and self-depreciation, and consequently experience a greater stress. Being unable to cope with stress efficiently creates risks in individuals in terms of health problems such as anxiety and depression. Healthcare professionals are required to evaluate life styles, difficulties and coping levels of immigrants in order to protect and develop their mental health. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(1.000: 56-66

  11. Stock returns and foreign investment in Brazil

    OpenAIRE

    Reis, Luciana; Meurer, Roberto; Da Silva, Sergio

    2008-01-01

    We examine the relationship between stock returns and foreign investment in Brazil, and find that the inflows of foreign investment boosted the returns from 1995 to 2005. There was a strong contemporaneous correlation, although not Granger-causality. Foreign investment along with the exchange rate, the influence of the world stock markets, and country risk can explain 73 percent of the changes that occurred in the stock returns over the period. We also find that positive feedback trading play...

  12. MIGRATION IMPACT ON ECONOMICAL SITUATION

    Directory of Open Access Journals (Sweden)

    Virginia COJOCARU

    2016-01-01

    Full Text Available This paper presents recent trends and flows of labor migration and its impact on economic and social life. Main aim of this research sets up the influence of the migration on the European economics and its competitiveness. Methods of research are: method of comparison, analysis method, method of deduction, method of statistics, modeling method. The economic impact of migration has been intensively studied but is still often driven by ill-informed perceptions, which, in turn, can lead to public antagonism towards migration. These negative views risk jeopardising efforts to adapt migration policies to the new economic and demographic challenges facing many countries. Migration Policy looks at the evidence for how immigrants affect the economy in three main areas: The labour market, public purse and economic growth. In Europe, the scope of labour mobility greatly increased within the EU/EFTA zones following the EU enlargements of 2004, 2007 and 2014-2015. This added to labour markets’ adjustment capacity. Recent estimates suggest that as much as a quarter of the asymmetric labour market shock – that is occurring at different times and with different intensities across countries – may have been absorbed by migration within a year.

  13. Vulnerable to HIV / AIDS. Migration.

    Science.gov (United States)

    Fernandez, I

    1998-01-01

    This special report discusses the impact of globalization, patterns of migration in Southeast Asia, gender issues in migration, the links between migration and HIV/AIDS, and spatial mobility and social networks. Migrants are particularly marginalized in countries that blame migrants for transmission of infectious and communicable diseases and other social ills. Effective control of HIV/AIDS among migrant and native populations requires a multisectoral approach. Programs should critically review the privatization of health care services and challenge economic models that polarize the rich and the poor, men and women, North and South, and migrant and native. Programs should recognize the equality between locals and migrants in receipt of health services. Countermeasures should have input from migrants in order to reduce the conditions that increase vulnerability to HIV/AIDS. Gender-oriented research is needed to understand women's role in migration. Rapid assessment has obscured the human dimension of migrants' vulnerability to HIV. Condom promotion is not enough. Migration is a major consequence of globalization, which holds the promise, real or imagined, of prosperity for all. Mass migration can be fueled by explosive regional developments. In Southeast Asia, migration has been part of the process of economic development. The potential to emigrate increases with greater per capita income. "Tiger" economies have been labor importers. Safe sex is not practiced in many Asian countries because risk is not taken seriously. Migrants tend to be used as economic tools, without consideration of social adjustment and sex behavior among singles.

  14. Income Inequality and Migration in Vietnam

    OpenAIRE

    NGUYEN, Tien Dung

    2012-01-01

    In this paper, we have analyzed the recent trends in income inequality, internal and international migrations and investigated the impact of migration on income distribution in Vietnam. Our analysis shows that the effects of migration on income inequality vary with different types of migration, depending on who migrate and where they migrate. Foreign remittances tend to flow toward more affluent households, and they increase income inequality. By contrast, domestic remittances accrue more to ...

  15. Maximizing ROI (return on information)

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, B.

    2000-05-01

    The role and importance of managing information are discussed, underscoring the importance by quoting from the report of the International Data Corporation, according to which Fortune 500 companies lost $ 12 billion in 1999 due to inefficiencies resulting from intellectual re-work, substandard performance , and inability to find knowledge resources. The report predicts that this figure will rise to $ 31.5 billion by 2003. Key impediments to implementing knowledge management systems are identified as : the cost and human resources requirement of deployment; inflexibility of historical systems to adapt to change; and the difficulty of achieving corporate acceptance of inflexible software products that require changes in 'normal' ways of doing business. The author recommends the use of model, document and rule-independent systems with a document centered interface (DCI), employing rapid application development (RAD) and object technologies and visual model development, which eliminate these problems, making it possible for companies to maximize their return on information (ROI), and achieve substantial savings in implementation costs.

  16. Laboratory studies of radionuclide migration in tuff

    International Nuclear Information System (INIS)

    Rundberg, R.S.; Mitchell, A.J.; Ott, M.A.; Thompson, J.L.; Triay, I.R.

    1989-01-01

    The movement of selected radionuclides has been observed in crushed tuff, intact tuff, and fractured tuff columns. Retardation factors and dispersivities were determined from the elution profiles. Retardation factors have been compared with those predicted on the basis of batch sorption studies. This comparison forms a basis for either validating distribution coefficients or providing evidence of speciation, including colloid formation. Dispersivities measured as a function of velocity provide a means of determining the effect of sorption kinetics or mass transfer on radionuclide migration. Dispersion is also being studied in the context of scaling symmetry to develop a basis for extrapolating from the laboratory scale to the field. 21 refs., 6 figs., 2 tabs

  17. The Returns to Human Capital Migration within the Department of Defense Civilian Internal Labor Market

    Science.gov (United States)

    2005-09-01

    a period of time from year 1 to year T † From Ronald Ehrenberg and Robert Smith. Modern Labor Economics : Theory and...Economic Literature 13 (June): 397- 433. Ehrenberg, Ronald G. and Robert S. Smith. 2003. Modern Labor Economics : Theory and Public Policy. 8th ed

  18. Migration and the epidemiological transition: insights from the Agincourt sub-district of northeast South Africa

    Science.gov (United States)

    Collinson, Mark A.; White, Michael J.; Bocquier, Philippe; McGarvey, Stephen T.; Afolabi, Sulaimon A.; Clark, Samuel J.; Kahn, Kathleen; Tollman, Stephen M.

    2014-01-01

    Background Migration and urbanization are central to sustainable development and health, but data on temporal trends in defined populations are scarce. Healthy men and women migrate because opportunities for employment and betterment are not equally distributed geographically. The disruption can result in unhealthy exposures and environments and income returns for the origin household. Objectives The objectives of the paper are to describe the patterns, levels, and trends of temporary migration in rural northeast South Africa; the mortality trends by cause category over the period 2000–2011; and the associations between temporary migration and mortality by broad cause of death categories. Method Longitudinal, Agincourt Health and Demographic Surveillance System data are used in a continuous, survival time, competing-risk model. Findings In rural, northeast South Africa, temporary migration, which involves migrants relocating mainly for work purposes and remaining linked to the rural household, is more important than age and sex in explaining variations in mortality, whatever the cause. In this setting, the changing relationship between temporary migration and communicable disease mortality is primarily affected by reduced exposure of the migrant to unhealthy conditions. The study suggests that the changing relationship between temporary migration and non-communicable disease mortality is mainly affected by increased livelihood benefits of longer duration migration. Conclusion Since temporary migration is not associated with communicable diseases only, public health policies should account for population mobility whatever the targeted health risk. There is a need to strengthen the rural health care system, because migrants tend to return to the rural households when they need health care. PMID:24848656

  19. Risk-return of Belgian SRI funds

    OpenAIRE

    Van Liedekerke, Luc; De Moor, Lieven; Vanwalleghem, Dieter

    2007-01-01

    We analyse the risk-return profile of Belgian SRI funds versus conventional investment funds. We apply a four-factor conditional Carhart model to establish whether there are significant differences in risk-return profile between an SRI portfolio and a conventional portfolio and test for learning effects in SRI funds. We show that there is no difference in risk-return profile between SRI and conventional funds. If return is not the problem, then what is it that limits the development of an SRI...

  20. Money growth and aggregate stock returns

    OpenAIRE

    Böing, Tobias; Stadtmann, Georg

    2016-01-01

    We empirically evaluate the predictive power of money growth measured by M2 for stock returns of the S&P 500 index. We use monthly US data and predict multiperiod returns over 1, 3, and 5 years with long-horizon regressions. In-sample regressions show that money growth is useful for predicting returns. Higher recent money growth has a significantly negative effect on subsequent returns of the S&P 500. An out-of-sample analysis shows that a simple model with money growth as a single predictor ...

  1. Human migration activities drive the fluctuation of ARGs : Case study of landfills in Nanjing, eastern China

    OpenAIRE

    Sun, Mingming; Ye, Mao; Schwab, Arthur P; Li, Xu; Wan, Jinzhong; Wei, Zhong; Wu, Jun; Friman, Ville-Petri; Liu, Kuan; Tian, Da; Liu, Manqiang; Li, Huixin; Hu, Feng; Jiang, Xin

    2016-01-01

    Landfills are perfect sites to study the effect of human migration on fluctuation of antibiotic resistance genes (ARGs) as they are the final destination of municipal waste. For example, large-scale human migration during the holidays is often accompanied by changes in waste dumping having potential effects on ARG abundance. Three landfills were selected to examine fluctuation in the abundance of fifteen ARGs and Intl1 genes for 14 months in Nanjing, eastern China. Mass human migration, the a...

  2. Migration, settlement change and health in post-apartheid South Africa: triangulating health and demographic surveillance with national census data.

    Science.gov (United States)

    Collinson, Mark A; Tollman, Stephen M; Kahn, Kathleen

    2007-08-01

    World population growth will be increasingly concentrated in the urban areas of the developing world; however, some scholars caution against the oversimplification of African urbanization noting that there may be "counter-urbanization" and a prevailing pattern of circular rural-urban migration. The aim of the paper is to examine the ongoing urban transition in South Africa in the post-apartheid period, and to consider the health and social policy implications of prevailing migration patterns. Two data sets were analysed, namely the South African national census of 2001 and the Agincourt health and demographic surveillance system. A settlement-type transition matrix was constructed on the national data to show how patterns of settlement have changed in a five-year period. Using the sub-district data, permanent and temporary migration was characterized, providing migration rates by age and sex, and showing the distribution of origins and destinations. The comparison of national and sub-district data highlight the following features: urban population growth, particularly in metropolitan areas, resulting from permanent and temporary migration; prevailing patterns of temporary, circular migration, and a changing gender balance in this form of migration; stepwise urbanization; and return migration from urban to rural areas. Policy concerns include: rural poverty exacerbated by labour migration; explosive conditions for the transmission of HIV; labour migrants returning to die in rural areas; and the challenges for health information created by chronically ill migrants returning to rural areas to convalesce. Lastly, suggestions are made on how to address the dearth of relevant population information for policy-making in the fields of migration, settlement change and health.

  3. [The productive structure and migration].

    Science.gov (United States)

    Fernandez, M

    1980-01-01

    The author discusses the possibility of determining the proper approach to the study of migration, with a focus on the importance of global, structural, and historical analysis of the phenomenon. A general theoretical outline is presented that tends to show migration as an integral part of the process of social change. The sociological focus on modernization as a theoretical guide influencing the study of migration in Latin America is evaluated. The concept of overpopulation is explained in relation to the migratory process, with reference to capitalist and non-capitalist forms of production.

  4. Migration of accreting giant planets

    Science.gov (United States)

    Robert, C.; Crida, A.; Lega, E.; Méheut, H.

    2017-09-01

    Giant planets forming in protoplanetary disks migrate relative to their host star. By repelling the gas in their vicinity, they form gaps in the disk's structure. If they are effectively locked in their gap, it follows that their migration rate is governed by the accretion of the disk itself onto the star, in a so-called type II fashion. Recent results showed however that a locking mechanism was still lacking, and was required to understand how giant planets may survive their disk. We propose that planetary accretion may play this part, and help reach this slow migration regime.

  5. MIGRATION – EFFECTS AND SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Raluca Cruceru

    2012-12-01

    Full Text Available There are three main flows that influence workforce performance—worker migration, the dissemination of knowledge, and overseas development assistance. For the present paper we decided to deal with the analyses of these three, yet mainly migration. We considered it to be one of the most important phenomenon existent on the market at this hour and with the highest negative impact on the economic and social situation. We presented a case study regarding the situation of migration in Romania and the main candidates to Romanian intelligence imports, the main issues and possible solutions to the problems encountered.

  6. Restricted grouper reproductive migrations support community-based management

    KAUST Repository

    Waldie, Peter A.

    2016-03-09

    Conservation commonly requires trade-offs between social and ecological goals. For tropical small-scale fisheries, spatial scales of socially appropriate management are generally small—the median no-take locally managed marine area (LMMA) area throughout the Pacific is less than 1 km2. This is of particular concern for large coral reef fishes, such as many species of grouper, which migrate to aggregations to spawn. Current data suggest that the catchment areas (i.e. total area from which individuals are drawn) of such aggregations are at spatial scales that preclude effective community-based management with no-take LMMAs. We used acoustic telemetry and tag-returns to examine reproductive migrations and catchment areas of the grouper Epinephelus fuscoguttatus at a spawning aggregation in Papua New Guinea. Protection of the resultant catchment area of approximately 16 km2 using a no-take LMMA is socially untenable here and throughout much of the Pacific region. However, we found that spawning migrations were skewed towards shorter distances. Consequently, expanding the current 0.2 km2 no-take LMMA to 1–2 km2 would protect approximately 30–50% of the spawning population throughout the non-spawning season. Contrasting with current knowledge, our results demonstrate that species with moderate reproductive migrations can be managed at scales congruous with spatially restricted management tools.

  7. The financial losses from the migration of nurses from Malawi

    Directory of Open Access Journals (Sweden)

    Muula Adamson S

    2006-11-01

    Full Text Available Abstract Background The migration of health professionals trained in Africa to developed nations has compromised health systems in the African region. The financial losses from the investment in training due to the migration from the developing nations are hardly known. Methods The cost of training a health professional was estimated by including fees for primary, secondary and tertiary education. Accepted derivation of formula as used in economic analysis was used to estimate the lost investment. Results The total cost of training an enrolled nurse-midwife from primary school through nurse-midwifery training in Malawi was estimated as US$ 9,329.53. For a degree nurse-midwife, the total cost was US$ 31,726.26. For each enrolled nurse-midwife that migrates out of Malawi, the country loses between US$ 71,081.76 and US$ 7.5 million at bank interest rates of 7% and 25% per annum for 30 years respectively. For a degree nurse-midwife, the lost investment ranges from US$ 241,508 to US$ 25.6 million at 7% and 25% interest rate per annum for 30 years respectively. Conclusion Developing countries are losing significant amounts of money through lost investment of health care professionals who emigrate. There is need to quantify the amount of remittances that developing nations get in return from those who migrate.

  8. The Migration Matrix: Marine Vertebrate Movements in Magnetic Coordinate Space

    Science.gov (United States)

    Horton, T. W.; Holdaway, R. N.; Clapham, P. J.; Zerbini, A. N.; Andriolo, A.; Hays, G. C.; Egevang, C.; Domeier, M. L.; Lucas, N.

    2011-12-01

    Determining how vertebrates navigate during their long-distance migrations remains one of the most enduring and fundamental challenges of behavioral ecology. It is widely accepted that spatial orientation relative to a reference datum is a fundamental requirement of long-distance return migration between seasonal habitats, and a variety of viable positional and directional orientation cues, including the sun, stars, and magnetic field, have been documented experimentally. However, a fundamental question remains unanswered: Are empirically observed migratory movements compatible with modern theoretical frameworks of spatial orientation? To address this question, we analysed leatherback turtle (Dermochelys coriacea), arctic tern (Sterna paradisaea), humpback whale (Megaptera novaeangliae), and great white shark (Carcharodon carcharias) track maps, frequency distribution diagrams and time-series plots of animal locations in spherical magnetic coordinate space. Our analyses indicates that, although individual migration tracks are spatially and temporally distinct, vertebrate movements are non-randomly distributed in all three spherical magnetic coordinates (i.e. intensity, inclination, and declination). Stop-over locations, migratory destinations, and re-orientation points occur at similar magnetic coordinate locations, relative to tagging areas, in all four species, suggesting that a common system of magnetic orientation likely informs the navigational behaviors of these phylogenetically diverse taxa. Although our analyses demonstrate that the experiment-derived 'magnetic map' goal orientation theoretical framework of animal navigation is compatible with remotely-sensed migration track data, they also indicate that magnetic information is complemented by spatially and temporally contingent celestial stimuli during navigation.

  9. Understanding the Impact of Migration on HIV Risk: An Analysis of Mexican Migrants' Sexual Practices, Partners, and Contexts by Migration Phase.

    Science.gov (United States)

    Zhang, Xiao; Rhoads, Natalie; Rangel, Maria Gudelia; Hovell, Melbourne F; Magis-Rodriguez, Carlos; Sipan, Carol L; Gonzalez-Fagoaga, J Eduardo; Martínez-Donate, Ana P

    2017-03-01

    HIV risk among Mexican migrants varies across migration phases (pre-departure, transit, destination, interception, and return), but there is limited knowledge about specific sexual behaviors, characteristics of sexual partners, and sexual contexts at different migration stages. To fill the gap, we used data from a cross-sectional population-based survey conducted in Tijuana, Mexico. Information on migration phase and last sexual encounter was collected from 1219 male migrants. Our findings suggest that compared to pre-departure migrants, repeat migrants returning from communities of origin were more likely to have sex with male partners, use substances before sex, and not use condoms; migrants in the transit phase in the Mexican border were more likely to have sex with casual partners and sex workers; and migrants in the interception phase were more likely to engage in anal sex and use substances before sex. Sexual behaviors, partners, and contexts vary significantly among migrants at different migration phases. Tailored HIV prevention programs targeting Mexican migrants need to be developed and implemented at all migration phases.

  10. Understanding the Impact of Migration on HIV Risk: An Analysis of Mexican Migrants’ Sexual Practices, Partners, and Contexts by Migration Phase

    Science.gov (United States)

    Zhang, Xiao; Rhoads, Natalie; Rangel, Maria Gudelia; Hovell, Melbourne F.; Magis-Rodriguez, Carlos; Sipan, Carol L.; Gonzalez-Fagoaga, J. Eduardo; Martínez-Donate, Ana P.

    2018-01-01

    HIV risk among Mexican migrants varies across migration phases (pre-departure, transit, destination, interception, and return), but there is limited knowledge about specific sexual behaviors, characteristics of sexual partners, and sexual contexts at different migration stages. To fill the gap, we used data from a cross-sectional population-based survey conducted in Tijuana, Mexico. Information on migration phase and last sexual encounter was collected from 1,219 male migrants. Our findings suggested that compared to pre-departure migrants, repeat migrants returning from communities of origin were more likely to have sex with male partners, use substances before sex, and not use condoms; migrants with a recent stay in the Mexican border were more likely to have sex with casual partners and sex workers; and migrants in the interception phase were more likely to engage in anal sex and use substances before sex. Sexual behaviors, partners, and contexts vary significantly among migrants at different migration phases. Tailored HIV prevention programs targeting Mexican migrants need to be developed and implemented at all migration phases. PMID:27888370

  11. Return of overseas contract workers and their rehabilitation and development in Kerala (India). A critical account of policies, performance and prospects.

    Science.gov (United States)

    Nair, P R

    1999-01-01

    This article reviews the situation of labor migrants from Kerala state, India, who were 40-60% of all contract workers in the Middle East and who returned after the mid-1980s. Descriptions are provided of the characteristics of return migrants, the Kerala economy, return migration policies, and impact studies of returnees. About 500,000 returned to Kerala. Returnees were middle aged, with low levels of education, skills, and experience. About 50% of returnees remained unemployed. The other 50% either retired or sought self-employment or other wage labor. Surveys conducted in 1985, 1987, 1993-93, and 1997 reveal that returnees peaked during the 1990s. By 1997, returnees to the Kadinamkulam panchayat included about one-sixth who were women. Most returnees had worked in Saudi Arabia, United Arab Emirates, and Kuwait. The reasons for return were poor working and living conditions, lack of opportunity or contract for staying longer, or forced repatriation. Upon return, 50% of the women and about 16% of the men remained unemployed. Return wages were about the same as before the migration. Returnees complained about the lack of support from government and society. Impact studies do not differentiate migration effects from development effects in general. Evaluation should focus on multidimensional impacts and individual attainment of emigration goals.

  12. SECTORAL RISK AND RETURN FOR COMPANIES IN ROMANIA

    Directory of Open Access Journals (Sweden)

    Anis Cecilia

    2012-12-01

    Full Text Available probability that cash flows or return will vary from expectations. Standard corporate finance theory supposes that a company chooses a capital structure that maximizes company value. A fundamental idea in finance is the relationship between risk and return. The greater the amount of risk that an investor is willing to take on, the greater the potential return. The reason for this is that investors need to be compensated for taking on additional risk. Why put capital at significant risk for a return that is no higher than the return on government bonds? Or expect higher than averages returns from low-risk activities? It is impossible to separate measuring the performance of a company from the risks that the management takes to achieve it.In most aspects of company operations, risk assessment plays a different but equally important, role. It is an integral part of informed decision taking in achieving performance. Risk assessment is involved from the highest level in strategic choices about what activities to undertake, what assets to buy or what markets to serve all the way to detailed operational decisions about whether to accept payment in foreign currencies and the adequacy of safety measures in the workplace. It plays a part whether or not an organization is aware of managing risk and many managers feel that their instinct and judgment are enough – a behavior risk. The danger is that this leaves company risk unplanned and unmanaged. This paper proposes a framework where we realized a study cases: we test if return on assets and return on equity has influence on the risk, both on long and short term. For this purposes, we conduct an empirical research that covers 59 selected companies traded at the Bucharest Stock Exchange within the time period 1999-2010. For this study our results reveal that dynamic global risk can be associated to a low intensity with total assets performance of the company’s. Investments efficiency and the

  13. Multifactor analysis of multiscaling in volatility return intervals.

    Science.gov (United States)

    Wang, Fengzhong; Yamasaki, Kazuko; Havlin, Shlomo; Stanley, H Eugene

    2009-01-01

    We study the volatility time series of 1137 most traded stocks in the U.S. stock markets for the two-year period 2001-2002 and analyze their return intervals tau , which are time intervals between volatilities above a given threshold q . We explore the probability density function of tau , P_(q)(tau) , assuming a stretched exponential function, P_(q)(tau) approximately e;(-tau;(gamma)) . We find that the exponent gamma depends on the threshold in the range between q=1 and 6 standard deviations of the volatility. This finding supports the multiscaling nature of the return interval distribution. To better understand the multiscaling origin, we study how gamma depends on four essential factors, capitalization, risk, number of trades, and return. We show that gamma depends on the capitalization, risk, and return but almost does not depend on the number of trades. This suggests that gamma relates to the portfolio selection but not on the market activity. To further characterize the multiscaling of individual stocks, we fit the moments of tau , mu_(m) identical with(tautau);(m);(1m) , in the range of 10portfolio optimization.

  14. International cooperation for Mars exploration and sample return

    Science.gov (United States)

    Levy, Eugene H.; Boynton, William V.; Cameron, A. G. W.; Carr, Michael H.; Kitchell, Jennifer H.; Mazur, Peter; Pace, Norman R.; Prinn, Ronald G.; Solomon, Sean C.; Wasserburg, Gerald J.

    1990-01-01

    The National Research Council's Space Studies Board has previously recommended that the next major phase of Mars exploration for the United States involve detailed in situ investigations of the surface of Mars and the return to earth for laboratory analysis of selected Martian surface samples. More recently, the European space science community has expressed general interest in the concept of cooperative Mars exploration and sample return. The USSR has now announced plans for a program of Mars exploration incorporating international cooperation. If the opportunity becomes available to participate in Mars exploration, interest is likely to emerge on the part of a number of other countries, such as Japan and Canada. The Space Studies Board's Committee on Cooperative Mars Exploration and Sample Return was asked by the National Aeronautics and Space Administration (NASA) to examine and report on the question of how Mars sample return missions might best be structured for effective implementation by NASA along with international partners. The committee examined alternatives ranging from scientific missions in which the United States would take a substantial lead, with international participation playing only an ancillary role, to missions in which international cooperation would be a basic part of the approach, with the international partners taking on comparably large mission responsibilities. On the basis of scientific strategies developed earlier by the Space Studies Board, the committee considered the scientific and technical basis of such collaboration and the most mutually beneficial arrangements for constructing successful cooperative missions, particularly with the USSR.

  15. Multifactor analysis of multiscaling in volatility return intervals

    Science.gov (United States)

    Wang, Fengzhong; Yamasaki, Kazuko; Havlin, Shlomo; Stanley, H. Eugene

    2009-01-01

    We study the volatility time series of 1137 most traded stocks in the U.S. stock markets for the two-year period 2001-2002 and analyze their return intervals τ , which are time intervals between volatilities above a given threshold q . We explore the probability density function of τ , Pq(τ) , assuming a stretched exponential function, Pq(τ)˜e-τγ . We find that the exponent γ depends on the threshold in the range between q=1 and 6 standard deviations of the volatility. This finding supports the multiscaling nature of the return interval distribution. To better understand the multiscaling origin, we study how γ depends on four essential factors, capitalization, risk, number of trades, and return. We show that γ depends on the capitalization, risk, and return but almost does not depend on the number of trades. This suggests that γ relates to the portfolio selection but not on the market activity. To further characterize the multiscaling of individual stocks, we fit the moments of τ , μm≡⟨(τ/⟨τ⟩)m⟩1/m , in the range of 10portfolio optimization.

  16. Maximizing your return on people.

    Science.gov (United States)

    Bassi, Laurie; McMurrer, Daniel

    2007-03-01

    Though most traditional HR performance metrics don't predict organizational performance, alternatives simply have not existed--until now. During the past ten years, researchers Laurie Bassi and Daniel McMurrer have worked to develop a system that allows executives to assess human capital management (HCM) and to use those metrics both to predict organizational performance and to guide organizations' investments in people. The new framework is based on a core set of HCM drivers that fall into five major categories: leadership practices, employee engagement, knowledge accessibility, workforce optimization, and organizational learning capacity. By employing rigorously designed surveys to score a company on the range of HCM practices across the five categories, it's possible to benchmark organizational HCM capabilities, identify HCM strengths and weaknesses, and link improvements or back-sliding in specific HCM practices with improvements or shortcomings in organizational performance. The process requires determining a "maturity" score for each practice, based on a scale of 1 (low) to 5 (high). Over time, evolving maturity scores from multiple surveys can reveal progress in each of the HCM practices and help a company decide where to focus improvement efforts that will have a direct impact on performance. The authors draw from their work with American Standard, South Carolina's Beaufort County School District, and a bevy of financial firms to show how improving HCM scores led to increased sales, safety, academic test scores, and stock returns. Bassi and McMurrer urge HR departments to move beyond the usual metrics and begin using HCM measurement tools to gauge how well people are managed and developed throughout the organization. In this new role, according to the authors, HR can take on strategic responsibility and ensure that superior human capital management becomes central to the organization's culture.

  17. Imaging characteristics of noncontained migrating disc fragment and cyst

    International Nuclear Information System (INIS)

    Eerens, I.; Demaerel, P.; Haven, F.; Wilms, G.; Loon, J. van; Calenbergh, F. van

    2001-01-01

    The purpose of this article is to review less common presentations of degenerative disc disease on MR imaging. The images of eight patients were retrospectively analyzed. Six of them had transligamentous (or noncontained) disc herniations, the fragments of which were located in the posterior epidural space in three of them. One patient had a transdural disc fragment and one patient had a disc cyst. The cyst was located in the ventrolateral epidural space. On T2-weighted images, the migrated disc fragment returned a higher signal than the disc of origin in 6 of 7 patients. The disc cyst returned a signal similar to that of cerebrospinal fluid. The MR appearances of disc fragments can be puzzling, particularly if they are located in the posterior epidural space. It is important to recognize the abnormalities in order to differentiate them from less common lesions such as hematoma, abscess and neurinoma. (orig.)

  18. Imaging characteristics of noncontained migrating disc fragment and cyst

    Energy Technology Data Exchange (ETDEWEB)

    Eerens, I.; Demaerel, P.; Haven, F.; Wilms, G. [Dept. of Radiology, University Hospitals, Leuven (Belgium); Loon, J. van; Calenbergh, F. van [Dept. of Neurosurgery, University Hospitals, Leuven (Belgium)

    2001-05-01

    The purpose of this article is to review less common presentations of degenerative disc disease on MR imaging. The images of eight patients were retrospectively analyzed. Six of them had transligamentous (or noncontained) disc herniations, the fragments of which were located in the posterior epidural space in three of them. One patient had a transdural disc fragment and one patient had a disc cyst. The cyst was located in the ventrolateral epidural space. On T2-weighted images, the migrated disc fragment returned a higher signal than the disc of origin in 6 of 7 patients. The disc cyst returned a signal similar to that of cerebrospinal fluid. The MR appearances of disc fragments can be puzzling, particularly if they are located in the posterior epidural space. It is important to recognize the abnormalities in order to differentiate them from less common lesions such as hematoma, abscess and neurinoma. (orig.)

  19. Numerical simulation research on gas migration with Y type ventilation

    Science.gov (United States)

    Gou, Yanan; Han, Xuezheng

    2018-01-01

    The ventilation way of the working face has a great influence to goaf flow field and gas migration, the existing U-shaped ventilation face wind serious overrun, Y type ventilation mode is put forward, and the mathematic control equation of the gas moving rule is established. Put the Gaozhuang coal mine west five mining area as the model, set up calculation model. And the gas concentration is simulated, the simulation results show that the Y type ventilation ways can intercept goaf gas into the corner on the working plane and return air lane, effectively avoid the work of top corner gas accumulation.

  20. Simplified method of evaluation of radionuclides migration in soil; Methode simplifiee d'evaluation de la migration de radionucleides dans le sol

    Energy Technology Data Exchange (ETDEWEB)

    Rozel, Ch

    1998-06-01

    In the frame of safety studies, it is useful to know the advance of an eventual release of radionuclides in ground water to determine the radiological impact on man by water ingestion, by irrigated plants ingestion and animals production ingestion (such milk or meat). The objectives of this report are to present the different physics phenomenons encountered during the migration, to list the different methods of doing ( to determine the radionuclides migration in soil), to choose one method and to check the results coherence with experience return. (N.C.)

  1. MRI of neuronal migration disorders

    International Nuclear Information System (INIS)

    Engelbrecht, V.

    1996-01-01

    Twenty-one MRI examinations of the brain were performed in 19 children with neuronal migration disorders. Multiplanar oriented spin-echo sequences were on a scanner with 1.5 T. In 8 children we performed an additional turbo-inversion recovery (TIR) sequence. Results of sonography or CT from five children were compared with MRI scans. Using the actual nomenclature, we found the following migration disorders: Lissencephaly (n=6), cobblestone lissencephaly with Walker-Warbung syndrome (WWS) (n=2), polymicrogyria and schizencephaly (n=2), focal heterotopia (n=5), diffuse heterotopie (n=2) and hemimegalencephaly (n=2). MRI was superior to CT and sonography in all children. Except for the two boys with WWS, the TIR sequence was the best to demonstrate the changes in migration disorder because of the high contrast between gray and white matter. We demonstrate the characteristic features of the different migration disorders and compare them with the existing literature. (orig.) [de

  2. The migration challenge for PAYG

    Czech Academy of Sciences Publication Activity Database

    Aslanyan, Gurgen

    2014-01-01

    Roč. 27, č. 4 (2014), s. 1023-1038 ISSN 0933-1433 Institutional support: RVO:67985998 Keywords : public pension s * PAYG * unskilled migration Subject RIV: AH - Economics Impact factor: 1.109, year: 2014

  3. The migration challenge for PAYG

    Czech Academy of Sciences Publication Activity Database

    Aslanyan, Gurgen

    2014-01-01

    Roč. 27, č. 4 (2014), s. 1023-1038 ISSN 0933-1433 Institutional support: PRVOUK-P23 Keywords : public pension s * PAYG * unskilled migration Subject RIV: AH - Economics Impact factor: 1.109, year: 2014

  4. Labour market frictions and migration

    NARCIS (Netherlands)

    Cremers, Jan

    2016-01-01

    The 4th contribution to the series INT-AR papers is dedicated to the methods of assessing labour market frictions. The paper provides a (brief) international comparison of the role of labour migration in solving these frictions.

  5. Fluid migration studies in salt

    International Nuclear Information System (INIS)

    Shefelbine, H.C.; Raines, G.E.

    1980-01-01

    This discussion will be limited to the migration of water trapped in the rock salt under the influence of the heat field produced by nuclear waste. This is of concern because hypotheticl scenarios have been advanced in which this fluid movement allows radionuclides to escape to the biosphere. While portions of these scenarios are supported by observation, none of the complete scenarios has been demonstrated. The objectives of the present fluid migration studies are two-fold: 1. determine the character of the trapped fluid in terms of quantity, habitat and chemical constituents; and 2. define the mechanisms that cause the fluid to migrate toward heat sources. Based on the observations to date, fluid migration will not have a major impact on repository integrity. However, the above objectives will be pursued until the impacts, if any, can be quantified

  6. Effort Estimation in BPMS Migration

    Directory of Open Access Journals (Sweden)

    Christopher Drews

    2018-04-01

    Full Text Available Usually Business Process Management Systems (BPMS are highly integrated in the IT of organizations and are at the core of their business. Thus, migrating from one BPMS solution to another is not a common task. However, there are forces that are pushing organizations to perform this step, e.g. maintenance costs of legacy BPMS or the need for additional functionality. Before the actual migration, the risk and the effort must be evaluated. This work provides a framework for effort estimation regarding the technical aspects of BPMS migration. The framework provides questions for BPMS comparison and an effort evaluation schema. The applicability of the framework is evaluated based on a simplified BPMS migration scenario.

  7. International migration and sustainable human development in eastern and southern Africa.

    Science.gov (United States)

    Oucho, J O

    1995-01-01

    International migration in eastern and southern Africa (ESA) is rarely addressed in population and development policies or regional organizations, and regional organizations must in the articulation of sustainable shared development identify the role of international migration. Poor quality data on international migration hampers analysis. Sustainable, shared, and human development within the region are subregional issues. Permanent migration is characterized among ESA countries as increasing demographic ethnic pluralism that may result in redrawing of territorial boundaries and further population movement. Portuguese and Arab settlement and integration in eastern areas resulted in coexistence, while European immigration to South Africa resulted in racial segregation. Modern colonial settlement and the aftermath of political conflict resulted in independent countries after the 1960s and outmigration of nonAfrican groups. Much of the labor migration in ESA is unskilled workers moving to South African mining regions. Labor migration to Zimbabwe and Zambia declined after the 1960s. The formation of the Common Market for ESA and the potential merger with the Preferential Trade Area and South African Development Community is a key approach to integration of migration into regional cooperation and shared development. Refugee movements create the most problems. Prior to 1992 ESA countries accounted for 83.4% of refugees, particularly in Mozambique, Ethiopia, and Somalia. Some countries blame poor economic performance on the deluge of refugees. Illegal migration is currently detected because of the required work permits, but the adoption of the Common Market would obscure this phenomenon. Human development is affected most by migrations related to drought, labor migration to strong economic areas, and return migration. The Inter-Governmental Authority on Drought and Development needs to become more active and establish better policies on nomadic and refugee movements and

  8. Roosts and migrations of swallows

    OpenAIRE

    Winkler, David W.

    2006-01-01

    Swallows of the north temperate zone display a wide variety of territorial behaviour during the breeding season, but as soon as breeding is over, they all appear to adopt a pattern of independent diurnal foraging interleaved with aggregation every night in dense roosts. Swallows generally migrate during the day, feeding on the wing. On many stretches of their annual journeys, their migrations can thus be seen as the simple spatial translation of nocturnal roost sites with foraging routes stra...

  9. International Student Migration to Germany

    OpenAIRE

    Donata Bessey

    2007-01-01

    This paper presents first empirical evidence on international student migration to Germany. I use a novel approach that analyzes student mobility using an augmented gravity equation and find evidence of strong network effects and of the importance of distance - results familiar from the empirical migration literature. However, the importance of disposable income in the home country does not seem to be too big for students, while the fact of being a politically unfree country decreases migrati...

  10. Effort Estimation in BPMS Migration

    OpenAIRE

    Drews, Christopher; Lantow, Birger

    2018-01-01

    Usually Business Process Management Systems (BPMS) are highly integrated in the IT of organizations and are at the core of their business. Thus, migrating from one BPMS solution to another is not a common task. However, there are forces that are pushing organizations to perform this step, e.g. maintenance costs of legacy BPMS or the need for additional functionality. Before the actual migration, the risk and the effort must be evaluated. This work provides a framework for effort estimation re...

  11. Return-to-Work Program for Injured Workers: Factors of Successful Return to Employment.

    Science.gov (United States)

    Awang, Halimah; Shahabudin, Sharifah Muhairah; Mansor, Norma

    2016-11-01

    This study examined the factors of successful return to employment among participants in the return to work program (RTW) following work-related injury. Data were obtained from the Social Security Organization database containing 9850 injured workers who underwent RTW in 2010 to 2013. About 65% had successfully returned to employment. Significant factors of successful return include gender, employer interest, motivation, age, intervention duration, and type of injury. Male and motivated employees were more likely to return to employment compared with female and unmotivated employees, respectively. Participants from interested employers were 23.22 times more likely to return to work than those from uninterested employers, whereas participants whose intervention period exceeded 5 months were 41% less likely to return to work compared with those whose intervention period was within 3 months. Appropriate strategy and enhanced collaboration between the stakeholders would improve the proportion of successful return to employment. © 2016 APJPH.

  12. Measures to facilitate the reintegration of returning migrant workers: international experiences.

    Science.gov (United States)

    Lohrmann, R

    1988-06-01

    Bilateral and multilateral measures implemented to assist migrants who return to their country of origin have been designed to respond to a number of different but specific situations. 2 bilateral agreements are briefly described: 1) an agreement between the Federal Republic of Germany and the Republic of Turkey signed in the early 1970s, and 2) an agreement between France and Algeria signed in 1980. 3 different types of multilateral activities are described: 1) the operation of the so-called Return of Talent program by the Intergovernmental Committee for Migration, 2) the Transfer of KNow-how Through Expatriate Nationals program of the UN Development Programme, and 3) the elaboration of a model machinery on return migration by the Organization for Economic Cooperation and Development. While the 1st 2 activities are operational programs, by which annually between 1000-2000 professionals are assisted in their permanent return to or temporary sojourn in their developing countries of origin, with the financial support of both the developed and the developing countries concerned, the 3rd initiative is a conceptual effort aimed at assisting governments to implement policy measures designed to make return migration commensurate with national development goals. 3 recent proposals include 1) the proposal for an international labor compensatory facility, 2) an international fund for vocational training, and 3) an international fund for manpower resources. A common factor shared by all these programs is that they have all involved on 1 side industrial receiving countries which feel themselves obliged to observe a number of principles guaranteed by law and which govern employment conditions and working relations. The reintegration measures implemented or proposed in cooperation with them have been adopted in full consideration of the prevailing standards of these countries, as different as they may be from 1 country to another. A common consideration has been that the

  13. Impact of return measures / Impacto de las medidas de retorno. Documento incluido en el Informe Anual sobre la Situación de la Integración Social de los Inmigrantes y Refugiados 2010

    Directory of Open Access Journals (Sweden)

    Ministerio de Trabajo e Inmigración

    2012-10-01

    Full Text Available The European Pact on Immigration and Asylum, October 2008, establishes two lines of work that affect returns: (1 returns to fight illegal immigration, (2 to favor synergies between migration and development with the countries of origin and transit. For this, the UE provides a European Fund for return for the period 2008-2013. The Spanish government in turn considers certain measures in that regard. Highlights include: the "return of social care", focused on people with high vulnerability profiles; and the "voluntary return plan," or productive. Other programs are funded by various regional governments. The article also speaks of external programs (return in the Andean axis, particularly in Ecuador, through the "welcome home" program (SENAMI. Finally, a comprehensive policy that links migration and development is considered.

  14. Return on Investment from Biochar Application

    Science.gov (United States)

    Current literature has yet to fully address the cost of biochar application or the return on investment to the grower. The objectives were to identify possible on-farm spreader equipment, spreader capacity, application expenses, and rate of return needed for growers to apply biochar economically. Bi...

  15. Aggregate Unemployment Decreases Individual Returns to Education

    Science.gov (United States)

    Ammermueller, Andreas; Kuckulenz, Anja; Zwick, Thomas

    2009-01-01

    Aggregate unemployment may affect individual returns to education through qualification-specific responses in participation and wage bargaining. This paper shows that an increase in regional unemployment by 1% decreases returns to education by 0.005 percentage points. This implies that higher skilled employees are better sheltered from labour…

  16. A Perishable Inventory Model with Return

    Science.gov (United States)

    Setiawan, S. W.; Lesmono, D.; Limansyah, T.

    2018-04-01

    In this paper, we develop a mathematical model for a perishable inventory with return by assuming deterministic demand and inventory dependent demand. By inventory dependent demand, it means that demand at certain time depends on the available inventory at that time with certain rate. In dealing with perishable items, we should consider deteriorating rate factor that corresponds to the decreasing quality of goods. There are also costs involved in this model such as purchasing, ordering, holding, shortage (backordering) and returning costs. These costs compose the total costs in the model that we want to minimize. In the model we seek for the optimal return time and order quantity. We assume that after some period of time, called return time, perishable items can be returned to the supplier at some returning costs. The supplier will then replace them in the next delivery. Some numerical experiments are given to illustrate our model and sensitivity analysis is performed as well. We found that as the deteriorating rate increases, returning time becomes shorter, the optimal order quantity and total cost increases. When considering the inventory-dependent demand factor, we found that as this factor increases, assuming a certain deteriorating rate, returning time becomes shorter, optimal order quantity becomes larger and the total cost increases.

  17. Slow return of displaced Southern Sudanese

    Directory of Open Access Journals (Sweden)

    Tim Morris

    2007-07-01

    Full Text Available The pace of repatriation of Sudanese refugees and return of IDP s to South Sudan has picked up but expectations at the time of the signing of the Comprehensive Peace Agreement (CPA CPA in January 2005 have yet to be realised. With all eyes on Darfur, assistance to sustain returns to South Sudan remains inadequate.

  18. Managing Returns in a Catalog Distribution Center

    Science.gov (United States)

    Gates, Joyce; Stuart, Julie Ann; Bonawi-tan, Winston; Loehr, Sarah

    2004-01-01

    The research team of the Purdue University in the United States developed an algorithm that considers several different factors, in addition to cost, to help catalog distribution centers process their returns more efficiently. A case study to teach the students important concepts involved in developing a solution to the returns disposition problem…

  19. 27 CFR 41.112 - Tax return.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Tax return. 41.112 Section 41.112 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF... States Deferred Payment of Tax in Puerto Rico on Tobacco Products § 41.112 Tax return. The internal...

  20. Economic and accounting rates of return

    NARCIS (Netherlands)

    Feenstra, D.W.; Wang, H.

    2000-01-01

    The rate of return on invested capital is a central concept in financial analysis. The purpose of calculating the rate of return on investment in general is to measure the financial performance, to assess the desirability of a project and to make decisions on the valuation of firms. Financial

  1. Predictability of Returns and Cash Flows

    OpenAIRE

    Ralph S.J. Koijen; Stijn Van Nieuwerburgh

    2010-01-01

    We review the literature on return and cash-flow growth predictability from the perspective of the present-value identity. We focus predominantly on recent work. Our emphasis is on U.S. aggregate stock return predictability, but we also discuss evidence from other asset classes and countries.

  2. Legal institutions, strategic default, and stock returns

    NARCIS (Netherlands)

    Favara, G.; Schroth, E.; Valta, P.

    2008-01-01

    This paper studies the impact of legal institutions on stock returns. More specifically, we examine how differences in debt enforcement and creditor protection around the world affect stock returns of individual firms. We hypothesize that if legal institutions prevent shareholders from engaging in

  3. Return to Experience and Initial Wage Level

    DEFF Research Database (Denmark)

    Sørensen, Kenneth Lykke; Vejlin, Rune Majlund

    This paper estimates the relationship between initial wage and return to experience. We use a Mincer-like wage model to nonparametrically estimate this relationship allowing for an unobservable individual permanent effect in wages and unobservable individual return to experience. The relationship...

  4. Return to experience and initial wage level

    DEFF Research Database (Denmark)

    Sørensen, K.L.; Vejlin, R.

    2014-01-01

    This paper estimates the relationship between initial wage and return to experience. We use a Mincer-like wage model to non-parametrically estimate this relationship allowing for an unobservable individual permanent effect in wages and unobservable individual return to experience. The relationshi...

  5. Returnable containers: an example of reverse logistics

    NARCIS (Netherlands)

    L.G. Kroon (Leo); G.M.C. Vrijens

    1996-01-01

    textabstractConsiders the application of returnable containers as an example of reverse logistics. A returnable container is a type of secondary packaging that can be used several times in the same form, in contrast with traditional cardboard boxes. For this equipment to be used, a system for the

  6. Return to the workforce following infective endocarditis

    DEFF Research Database (Denmark)

    Butt, Jawad H.; Kragholm, Kristian; Dalager-Pedersen, Michael

    2018-01-01

    Background The ability to return to work after infective endocarditis (IE) holds important socioeconomic consequences for both patients and society, yet data on this issue are sparse. We examined return to the workforce and associated factors in IE patients of working age. Methods Using Danish...

  7. Parasitic diseases in the returning traveller

    African Journals Online (AJOL)

    2009-06-11

    Jun 11, 2009 ... exception is infection with schistosomiasis after leisure activities in infested freshwater. (the water sports enthusiast returning from a sojourn on Lake Malawi .... are harbouring a 'blind passenger' from abroad. However, long-term travellers, both private or business, should be screened on return. A thorough ...

  8. Economic Return of Clinical Trials Performed Under the Pediatric Exclusivity Program

    Science.gov (United States)

    Li, Jennifer S.; Eisenstein, Eric L.; Grabowski, Henry G.; Reid, Elizabeth D.; Mangum, Barry; Schulman, Kevin A.; Goldsmith, John V.; Murphy, M. Dianne; Califf, Robert M.; Benjamin, Daniel K.

    2009-01-01

    Context In 1997, Congress authorized the Food and Drug Administration (FDA) to grant 6 month extensions of marketing rights through the Pediatric Exclusivity program if industry sponsors complete FDA-requested pediatric trials. The program has been praised for creating incentives for studies in children; it has been criticized as a “windfall” to the innovator drug industry. This critique has been a substantial part of Congressional debate on the program, which is due to sunset in 2007. Objective To quantify the economic return to industry for completing Pediatric Exclusivity. Design Cohort study of programs conducted for Pediatric Exclusivity. We selected 9 drugs that were granted Pediatric Exclusivity. From the final study reports submitted to FDA, we obtained key elements of the clinical trial design and study operations. We estimated the cost of performing each study and converted these into estimates of after-tax cash outflows. We obtained 3-year market sales and converted these into estimates of after-tax cash inflows based upon 6 months of additional market protection. We then calculated the net economic return (cash inflows less outflows) and ratio net return to costs (net economic return divided by cash outflows) for each product. Main Outcome Measures Net economic return and ratio of net return to cost. Results The indications studied reflected a broad representation of the program: asthma, tumors, attention deficit disorder, hypertension, depression/generalized anxiety disorder, diabetes, gastroesophageal reflux, bacterial infection, and bone mineralization. The distribution of net economic return for 6 months of exclusivity varied substantially among products [net return ranged from (−)$8.9 million to (+)$507.9 million; ratio of return to cost ranged from −0.68 to 73.6] Conclusions The economic return for pediatric exclusivity is highly variable. Pediatric Exclusivity, as an incentive to complete much-needed clinical trials in children, can

  9. Estimates of potential radionuclide migration at the Bullion site

    International Nuclear Information System (INIS)

    Brikowski, T.H.

    1992-04-01

    The Bullion site in Area 20 of the Nevada Test Site has been selected for an intensive study of the hydrologic consequences of underground testing, including subsequent radionuclide migration. The bulk of the chimney and cavity lie in zeolitized tuffs of low hydraulic conductivity, while the base of the cavity may extend downward into more conductive rhyolite flows. A mathematical analog to the Bullion setting is used here to estimate expected radionuclide migration rates and concentrations. Because of a lack of hydrologic data at the site, two contrasting scenarios are considered. The first is downward-transport, in which downward hydraulic gradients flush chimney contents into the conductive underlying units, enhancing migration. The other is upward-transport, in which upward gradients tend to drive chimney contents into the low-conductivity zeolitized tuffs, discouraging migration. In the downward-transport scenario, radionuclide travel times and concentrations are predicted to be similar to those encountered at Cheshire, requiring approximately 10 years to reach a proposed well 300 m downgradient. The upward transport scenario yields predicted travel times on the order of 2,000 years to the downgradient well. The most likely scenario is a combination of these results, with vertical movement playing a limited role. Radionuclides injected directly into the rhyolites should migrate laterally very quickly, with travel times as in the downward-transport scenario. Those in the zeolitized tuff-walled portion of the chimney should migrate extremely slowly, as in the upward-transport scenario

  10. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans-Saharan m......Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...... in the population of the species. The papers show that adult and juvenile birds can use different migration strategies depending on time of season and prevailing conditions. Also, the fuel loads of some individuals were theoretically sufficient for a direct flight to important goal area, but whether they do so...

  11. Investigation on nuclide migration behaviors

    International Nuclear Information System (INIS)

    Baik, Minhoon; Park, Chungkyun; Kim, Seungsoo

    2012-04-01

    In this study, we investigated the properties of geochemical reactions and sorption of high-level radionuclides and highly-mobile radionuclides in deep geological disposal environments. We also analyzed the dissolution properties of pyro wastes and constructed databases for the geochemical reactions and sorption for the safety assessment of HLW disposal. Technologies for measuring diffusion depths of radionuclides through fracture surfaces and rock matrix were developed in KURT conditions and their diffusion properties were analyzed and evaluated. The combined reactions of radionuclide/mineral/microbe in deep disposal environments were investigated and the effects of microbe on the radionuclide migration and disposal system behaviors were evaluated. In-situ solute migration system and on-line monitoring system were installed in KURT and the migration and retardation behaviors of various solutes and their interaction with fracture-filling materials were investigated. Basic properties of KURT groundwater colloids were analyzed using various methods. In addition, in-situ colloid migration experiments through a rock fracture were carried out and the developed migration model was verified. We have participated in Colloid Formation and Migration (CFM) international joint project in GTS and obtained reliability for our research results by comparing research results each other

  12. The Risk Return Relationship: Evidence from Index Return and Realised Variance Series

    OpenAIRE

    Minxian Yang

    2014-01-01

    The risk return relationship is analysed in bivariate models for return and realised variance(RV) series. Based on daily time series from 21 international market indices for more than 13 years (January 2000 to February 2013), the empirical findings support the arguments of risk return tradeoff, volatility feedback and statistical balance. It is reasoned that the empirical risk return relationship is primarily shaped by two important data features: the negative contemporaneous correlation betw...

  13. Return currents in solar flares - Collisionless effects

    Science.gov (United States)

    Rowland, H. L.; Vlahos, L.

    1985-01-01

    If the primary, precipitating electrons in a solar flare are unstable to beam plasma interactions, it is shown that strong Langmuir turbulence can seriously modify the way in which a return current is carried by the background plasma. In particular, the return (or reverse) current will not be carried by the bulk of the electrons, but by a small number of high velocity electrons. For beam/plasma densities greater than 0.01, this can reduce the effects of collisions on the return current. For higher density beams where the return current could be unstable to current driven instabilities, the effects of strong turbulence anomalous resistivity is shown to prevent the appearance of such instabilities. Again in this regime, how the return current is carried is determined by the beam generated strong turbulence.

  14. Poetic Return in Afghanistan Persian Poem

    Directory of Open Access Journals (Sweden)

    Esmaeil Shafagh

    2012-11-01

    Full Text Available Abstract Poetic return movement was started by a group of poets like Moshtagh and Shole Esfehani in the second half of 12 century. Their goal was restoring Persian poem and deliverance of Hindi style decline. Esfahan’s poets initiative was considered only in Iran but in other Persian language and literature areas like India, Afghanistan and Transoxiana it was ignored. After the failure of constitutional Movement in Afghanistan, motion similar poetic return was happened that caused poetic themes, which had gone towards modernism, return to Hindi style again.The present paper attempts to analyze the poetic atmosphere in Afghanistan synchronous the poetic return movement in Iran and investigate socio- political backgrounds of return to Hindi style in Afghanistan after constitution failure.

  15. 3D Multi‐source Least‐squares Reverse Time Migration

    KAUST Repository

    Dai, Wei; Boonyasiriwat, Chaiwoot; Schuster, Gerard T.

    2010-01-01

    : random time shift, random source polarity and random source location selected from a pre‐designed table. Numerical tests for the 3D SEG/EAGE Overthrust model show that multi‐source LSRTM can suppress migration artifacts in the migration image and remove

  16. Moderating Poverty: The Role of Remittances from Migration in ...

    African Journals Online (AJOL)

    sulaiman.adebowale

    the remittances do not have a significant moderating effect on poverty in .... also indicates that migration is selective by access to wealth (Gubert 2002). Here, the ... lowest-income rural households received the most remittance because they .... observed, educated African women have considerable ability to remit materially.

  17. On the simulation of subsurface migration of radionuclides

    International Nuclear Information System (INIS)

    Angermann, L.

    1989-01-01

    The consequences of the migration of contaminants through the groundwater flow system can be estimated by means of the analytical solutions of the corresponding initial-boundary value problems. The paper states analytical solutions of some selected problems which have not been considered in this form as yet and it describes a conception for the reliable computation of the required function values. (author)

  18. 75 FR 76940 - Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic...

    Science.gov (United States)

    2010-12-10

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Parts 1 and 301 [REG-100194-10] RIN 1545-BJ52 Specified Tax Return Preparers Required To File Individual Income Tax Returns Using Magnetic... for ``specified tax return prepares,''. FOR FURTHER INFORMATION CONTACT: Keith L. Brau at (202) 622...

  19. 26 CFR 1.6013-2 - Joint return after filing separate return.

    Science.gov (United States)

    2010-04-01

    ... the case of a joint return made under section 6013(b), the period of limitations provided in sections... (c)(1) of this section, relating to the application of sections 6501 and 6651 with respect to a joint... 26 Internal Revenue 13 2010-04-01 2010-04-01 false Joint return after filing separate return. 1...

  20. Collective cell migration drives morphogenesis of the kidney nephron.

    Directory of Open Access Journals (Sweden)

    Aleksandr Vasilyev

    2009-01-01

    Full Text Available Tissue organization in epithelial organs is achieved during development by the combined processes of cell differentiation and morphogenetic cell movements. In the kidney, the nephron is the functional organ unit. Each nephron is an epithelial tubule that is subdivided into discrete segments with specific transport functions. Little is known about how nephron segments are defined or how segments acquire their distinctive morphology and cell shape. Using live, in vivo cell imaging of the forming zebrafish pronephric nephron, we found that the migration of fully differentiated epithelial cells accounts for both the final position of nephron segment boundaries and the characteristic convolution of the proximal tubule. Pronephric cells maintain adherens junctions and polarized apical brush border membranes while they migrate collectively. Individual tubule cells exhibit basal membrane protrusions in the direction of movement and appear to establish transient, phosphorylated Focal Adhesion Kinase-positive adhesions to the basement membrane. Cell migration continued in the presence of camptothecin, indicating that cell division does not drive migration. Lengthening of the nephron was, however, accompanied by an increase in tubule cell number, specifically in the most distal, ret1-positive nephron segment. The initiation of cell migration coincided with the onset of fluid flow in the pronephros. Complete blockade of pronephric fluid flow prevented cell migration and proximal nephron convolution. Selective blockade of proximal, filtration-driven fluid flow shifted the position of tubule convolution distally and revealed a role for cilia-driven fluid flow in persistent migration of distal nephron cells. We conclude that nephron morphogenesis is driven by fluid flow-dependent, collective epithelial cell migration within the confines of the tubule basement membrane. Our results establish intimate links between nephron function, fluid flow, and morphogenesis.